Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-05-12 08:55

Modified

2026-05-12 09:14

Summary

Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding

Details

In PHP versions 8.4. before 8.4.21 and 8.5. before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "php",
        "purl": "pkg:bitnami/php"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.4.0"
            },
            {
              "fixed": "8.4.21"
            },
            {
              "introduced": "8.5.0"
            },
            {
              "fixed": "8.5.6"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:M/U:Amber",
          "type": "CVSS_V4"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-6104"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:php:php:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when\u00a0strncasecmp()\u00a0returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.\u00a0Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.",
  "id": "BIT-php-2026-6104",
  "modified": "2026-05-12T09:14:35.689Z",
  "published": "2026-05-12T08:55:59.545Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/php/php-src/security/advisories/GHSA-74r9-qxhc-fx53"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6104"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding"
}

CVE-2026-6104 (GCVE-0-2026-6104)

Vulnerability from cvelistv5 – Published: 2026-05-10 04:35 – Updated: 2026-05-11 13:04

Title

Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding

Summary

In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.

Severity ?

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/RE:M/U:Amber

CWE

CWE-125 - Out-of-bounds Read

Assigner

php

References

1 reference

URL	Tags
https://github.com/php/php-src/security/advisorie…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
PHP Group	PHP	Affected: 8.4.* , < 8.4.21 (semver) Affected: 8.5.* , < 8.5.6 (semver)

Date Public ?

2026-05-07 00:00

Credits

Akshay Jain Ilija Tovilo

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-6104",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-11T13:04:44.572023Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-11T13:04:58.462Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageName": "mbstring",
          "product": "PHP",
          "vendor": "PHP Group",
          "versions": [
            {
              "lessThan": "8.4.21",
              "status": "affected",
              "version": "8.4.*",
              "versionType": "semver"
            },
            {
              "lessThan": "8.5.6",
              "status": "affected",
              "version": "8.5.*",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Akshay Jain"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Ilija Tovilo"
        }
      ],
      "datePublic": "2026-05-07T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to \u003ccode\u003emb_convert_encoding()\u003c/code\u003e or related mbstring functions, the code incorrectly assumes that when\u0026nbsp;\u003ccode\u003estrncasecmp()\u003c/code\u003e\u0026nbsp;returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.\u003cspan\u003e\u0026nbsp;Affected functions include \u003c/span\u003e\u003ccode\u003emb_convert_encoding()\u003c/code\u003e\u003cspan\u003e, \u003c/span\u003e\u003ccode\u003emb_detect_encoding()\u003c/code\u003e\u003cspan\u003e, \u003c/span\u003e\u003ccode\u003emb_convert_variables()\u003c/code\u003e\u003cspan\u003e, and \u003c/span\u003e\u003ccode\u003emb_detect_order()\u003c/code\u003e\u003cspan\u003e, as well as the \u003c/span\u003e\u003ccode\u003embstring.detect_order\u003c/code\u003e\u003cspan\u003e and \u003c/span\u003e\u003ccode\u003embstring.http_output\u003c/code\u003e\u003cspan\u003e INI settings.\u003c/span\u003e"
            }
          ],
          "value": "In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when\u00a0strncasecmp()\u00a0returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.\u00a0Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "AMBER",
            "subAvailabilityImpact": "LOW",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/RE:M/U:Amber",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "MODERATE"
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          "format": "CVSS",
          "scenarios": [
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              "lang": "en",
              "value": "GENERAL"
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      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125 Out-of-bounds Read",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-10T04:35:17.328Z",
        "orgId": "dd77f84a-d19a-4638-8c3d-a322d820ed2b",
        "shortName": "php"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/php/php-src/security/advisories/GHSA-74r9-qxhc-fx53"
        }
      ],
      "source": {
        "advisory": "GHSA-74r9-qxhc-fx53",
        "discovery": "EXTERNAL"
      },
      "title": "Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "dd77f84a-d19a-4638-8c3d-a322d820ed2b",
    "assignerShortName": "php",
    "cveId": "CVE-2026-6104",
    "datePublished": "2026-05-10T04:35:17.328Z",
    "dateReserved": "2026-04-11T04:15:03.938Z",
    "dateUpdated": "2026-05-11T13:04:58.462Z",
    "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.

Detection rules are retrieved from Rulezet.

Action not permitted

Vulnerability from bitnami_vulndb

CVE-2026-6104 (GCVE-0-2026-6104)

Tags

Sightings

Nomenclature