Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-49114

CVE-2026-49114MEDIUM

ONNX symlink-following and path-traversal arbitrary file write

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   L   L   N   N   A   N   H   H    6.8   .0016    4.4     —

AFFECTED
  Product  Versions     Fixed
  ONNX     unspecified  1.21.0

TIMELINE
  May 27  Reserved by cisa-cg
  Aug 21  Published (CNA: cisa-cg)
  Sep 16  EXPLOIT PUBLISHED — CVE-2026-49114 (ONNX). Public exploit reference added.

CWE-22, CWE-59, CWE-367 · CNA: cisa-cg · CVSS v4.0 · 3 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 27, 2026	Reserved	Reserved by cisa-cg
August 21, 2026	Published	Published (CNA: cisa-cg)
September 16, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-49114 (ONNX). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
ONNX	ONNX	—	—	1.21.0

Weaknesses

CWE-22 · CWE-59 · CWE-367

References (3)

https://github.com/onnx/onnx/security/advisories/GHSA-q56x-g2fj-4rj6 [Exploit, Vendor Advisory]
https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-233-01.json [VDB Entry]
https://www.cve.org/CVERecord?id=CVE-2026-49114 [Third Party Advisory, VDB Entry]

Authoritative record: CVE-2026-49114 at cve.org

Vendors: onnx

Weaknesses: CWE-22 · CWE-59 · CWE-367

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-49114 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.