PYSEC-2026-2781

Vulnerability from pysec - Published: 2026-07-13 15:46 - Updated: 2026-07-13 16:05
VLAI
Details

Summary

A memory-safety vulnerability in Open Babel's SMILES parser caused a heap buffer overflow when reading a crafted input string.

Details

The flaw was in OBSmilesParser::ParseSmiles. A malformed SMILES input caused the parser to write past the end of a heap-allocated buffer.

Impact

Open Babel is a C++ library and CLI used to read and write chemistry file formats; it is shipped by Linux distributions and embedded in services that may parse untrusted input. Triggering this vulnerability requires the victim to parse a malicious SMILES string with the obabel tool, the OBConversion API, or any of the language bindings (Python, Ruby, Java, R, Perl, C#, PHP). SMILES strings are commonly passed on the command line and through scripted pipelines, so this primitive is especially reachable.

Affected versions

All releases up to and including 3.1.1.

Patched version

3.2.0 (released 2026-05-26).

Patch

Fix commit: https://github.com/openbabel/openbabel/commit/b34cd604 Originally reported as #2831; fixes consolidated in #2913.

A minimized reproducer for this CVE is checked in under test/files/fuzz_regress/ and is exercised on every CI build under ASAN+UBSAN by the fuzzregresstest harness.

Credit

Reported via OSS-Fuzz.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Impacted products
Name purl
openbabel pkg:pypi/openbabel
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "openbabel",
        "purl": "pkg:pypi/openbabel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.2.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8",
        "1.8.1",
        "1.8.2",
        "1.8.3",
        "1.8.4",
        "2.4.0",
        "2.4.1",
        "3.0.0",
        "3.0.0a1",
        "3.1.1",
        "3.1.1.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2025-10996",
    "GHSA-j35x-w4gj-pf7w"
  ],
  "details": "### Summary\n\nA memory-safety vulnerability in Open Babel\u0027s SMILES parser caused a\nheap buffer overflow when reading a crafted input string.\n\n### Details\n\nThe flaw was in `OBSmilesParser::ParseSmiles`. A malformed SMILES\ninput caused the parser to write past the end of a heap-allocated\nbuffer.\n\n### Impact\n\nOpen Babel is a C++ library and CLI used to read and write chemistry\nfile formats; it is shipped by Linux distributions and embedded in\nservices that may parse untrusted input. Triggering this vulnerability\nrequires the victim to parse a malicious SMILES string with the\n`obabel` tool, the `OBConversion` API, or any of the language\nbindings (Python, Ruby, Java, R, Perl, C#, PHP). SMILES strings are\ncommonly passed on the command line and through scripted pipelines,\nso this primitive is especially reachable.\n\n### Affected versions\n\nAll releases up to and including 3.1.1.\n\n### Patched version\n\n3.2.0 (released 2026-05-26).\n\n### Patch\n\nFix commit: https://github.com/openbabel/openbabel/commit/b34cd604\nOriginally reported as #2831; fixes consolidated in #2913.\n\nA minimized reproducer for this CVE is checked in under\n`test/files/fuzz_regress/` and is exercised on every CI build under\nASAN+UBSAN by the `fuzzregresstest` harness.\n\n### Credit\n\nReported via OSS-Fuzz.",
  "id": "PYSEC-2026-2781",
  "modified": "2026-07-13T16:05:18.037108Z",
  "published": "2026-07-13T15:46:25.561422Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/openbabel/openbabel/security/advisories/GHSA-j35x-w4gj-pf7w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-10996"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openbabel/openbabel/issues/2831"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openbabel/openbabel/pull/2913"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openbabel/openbabel/commit/b34cd604"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/openbabel/openbabel"
    },
    {
      "type": "WEB",
      "url": "https://github.com/user-attachments/files/22318556/poc.zip"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?ctiid.325924"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?id.325924"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?submit.654060"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/openbabel"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-j35x-w4gj-pf7w"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Open Babel has heap buffer overflow in SMILES OBSmilesParser::ParseSmiles"
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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