CVE-2026-34445 | ONNX: Malicious ONNX models can crash servers by exploiting unprotected object settings.

Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to version 1.21.0, the ExternalDataInfo class in ONNX was using Python’s setattr() function to load metadata (like file paths or data lengths) directly from an ONNX model file. It didn’t check if the "keys" in the file were valid. Due to this, an attacker could craft a malicious model that overwrites internal object properties. This issue has been patched in version 1.21.0.

Published: 2026-04-01 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-34445 is rated Moderate Risk (48.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.19%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-34445

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-26 0.06% 0.19% +0.13%
2 2026-04-07 0.04% 0.06% +0.02%
3 2026-04-02 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-34445

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 4.7 [email protected]

Weakness enumeration for CVE-2026-34445

GitHub Security Advisory for CVE-2026-34445

GHSA-538c-55jv-c5g9 · Severity: high · Ecosystem: pip — ONNX: Malicious ONNX models can crash servers by exploiting unprotected object settings.

OS Trackers for CVE-2026-34445

vendor priority summary link
debian not yet assigned CVE-2026-34445 not yet assigned priority: Debian including 1 source packages (onnx), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-34445
redhat medium — https://access.redhat.com/security/cve/CVE-2026-34445
ubuntu medium CVE-2026-34445 medium priority: Ubuntu including 1 source packages (onnx), 4 status rows across 4 suites (jammy, noble, questing, upstream): needs-triage 4. https://ubuntu.com/security/CVE-2026-34445

Affected software / configurations for CVE-2026-34445

Vendor Product Version Raw CPE
linuxfoundation onnx < 1.21.0 cpe:2.3:a:linuxfoundation:onnx:*:*:*:*:*:*:*:*

References for CVE-2026-34445

cvelogic Threat Intelligence