Vulnerability-Lookup

GHSA-72R6-P2X3-G9GJ

Vulnerability from github – Published: 2026-03-17 00:31 – Updated: 2026-03-17 03:30

Details

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.

The heap overflow occurs when class names exceed the initial 512-byte allocation.

The base64 decoder could read past the buffer end on trailing newlines.

strtok mutated n->type_id in place, corrupting shared node data.

A memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-4177"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-16T23:16:21Z",
    "severity": null
  },
  "details": "YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.\n\nThe heap overflow occurs when class names exceed the initial 512-byte allocation.\n\nThe base64 decoder could read past the buffer end on trailing newlines.\n\nstrtok mutated n-\u003etype_id in place, corrupting shared node data.\n\nA memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string \u0027a\u0027 was leaked on early return.",
  "id": "GHSA-72r6-p2x3-g9gj",
  "modified": "2026-03-17T03:30:21Z",
  "published": "2026-03-17T00:31:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4177"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/03/16/6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-4177 (GCVE-0-2026-4177)

Vulnerability from cvelistv5 – Published: 2026-03-16 22:30 – Updated: 2026-03-17 01:34

Title

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter

Summary

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter. The heap overflow occurs when class names exceed the initial 512-byte allocation. The base64 decoder could read past the buffer end on trailing newlines. strtok mutated n->type_id in place, corrupting shared node data. A memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.

Severity ?

No CVSS data available.

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

CPANSec

References

URL

Tags

	https://github.com/cpan-authors/YAML-Syck/commit/…	patch
	https://metacpan.org/release/TODDR/YAML-Syck-1.37…	release-notes

Impacted products

	Vendor	Product	Version
	TODDR	YAML::Syck	Affected: 0 , ≤ 1.36 (custom)

Credits

Todd Rinaldo

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-03-17T01:34:04.213Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/03/16/6"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "packageName": "YAML-Syck",
          "product": "YAML::Syck",
          "programFiles": [
            "emitter.c",
            "handler.c",
            "perl_common.h",
            "perl_syck.h"
          ],
          "programRoutines": [
            {
              "name": "YAML::Syck::yaml_syck_emitter_handler()"
            },
            {
              "name": "YAML::Syck::syck_base64dec()"
            },
            {
              "name": "YAML::Syck::yaml_syck_parser_handler()"
            },
            {
              "name": "YAML::Syck::syck_hdlr_add_anchor()"
            }
          ],
          "repo": "https://github.com/cpan-authors/YAML-Syck",
          "vendor": "TODDR",
          "versions": [
            {
              "lessThanOrEqual": "1.36",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Todd Rinaldo"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.\n\nThe heap overflow occurs when class names exceed the initial 512-byte allocation.\n\nThe base64 decoder could read past the buffer end on trailing newlines.\n\nstrtok mutated n-\u003etype_id in place, corrupting shared node data.\n\nA memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string \u0027a\u0027 was leaked on early return."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "CWE-122 Heap-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-16T22:30:25.367Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to version 1.37 or higher."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-4177",
    "datePublished": "2026-03-16T22:30:25.367Z",
    "dateReserved": "2026-03-14T19:36:56.710Z",
    "dateUpdated": "2026-03-17T01:34:04.213Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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

GHSA-72R6-P2X3-G9GJ

CVE-2026-4177 (GCVE-0-2026-4177)

Tags

Sightings

Nomenclature