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CVE-2026-49114 (GCVE-0-2026-49114)

Vulnerability from cvelistv5 – Published: 2026-08-21 16:10 – Updated: 2026-08-21 16:43
VLAI
Title
ONNX symlink-following and path-traversal arbitrary file write
Summary
In ONNX before 1.21.0, the 'save_external_data' function builds the external-data file path from the model's external_data location field and opens it for writing without 'O_NOFOLLOW/O_EXCL', after a non-atomic 'os.path.isfile()' check. A local attacker with write access to the directory where a victim serializes external data can deterministically pre-plant a symlink that is being followed, causing the victim's write to append to any file the victim can write, e.g. ~/.ssh/authorized_keys, cron files, or application configs. Fixed in 1.21.0.
Severity
7.1 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
6.8 (Medium)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · cisa-cg (v2.0.3)
Decision recorded 2026-05-27 16:00 UTC
CWE
  • CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  • CWE-59 - Improper Link Resolution Before File Access ('Link Following')
Assigner
References
Impacted products
Vendor Product Version CPE status
ONNX ONNX Affected: 0 , < 1.21.0 (custom)
Unaffected: 1.21.0
guessed Create a notification for this product.
Date Public
2026-03-31 00:00
Credits
tsigouris007 kpatsakis
Show details on NVD website
To clipboard 

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        "assignerShortName": "cisa-cg",
        "cveId": "CVE-2026-49114",
        "datePublished": "2026-08-21T16:10:56.241Z",
        "dateReserved": "2026-05-27T16:19:04.848Z",
        "dateUpdated": "2026-08-21T16:43:10.933Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


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.