CVE-2026-49114
ONNX symlink-following and path-traversal arbitrary file write
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.
INFO
Published Date :
Aug. 21, 2026, 4:17 p.m.
Last Modified :
Aug. 21, 2026, 5:16 p.m.
Remotely Exploit :
No
Source :
9119a7d8-5eab-497f-8521-727c672e3725
Affected Products
The following products are affected by CVE-2026-49114
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 9119a7d8-5eab-497f-8521-727c672e3725 | |||||
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 9119a7d8-5eab-497f-8521-727c672e3725 | ||||
| CVSS 4.0 | MEDIUM | 9119a7d8-5eab-497f-8521-727c672e3725 |
Solution
- Update ONNX to version 1.21.0 or later.
- Ensure external data locations are protected.
- Validate file writing operations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49114.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49114 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-49114
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-49114 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49114 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 21, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-49114', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-21T16:42:42.598941Z'} -
New CVE Received by 9119a7d8-5eab-497f-8521-727c672e3725
Aug. 21, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'ONNX', 'product': 'ONNX', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.21.0', 'versionType': 'custom'}, {'status': 'unaffected', 'version': '1.21.0'}], 'defaultStatus': 'unknown'}] Added SSVC {'id': 'CVE-2026-49114', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-05-27T16:00:11.944488Z'} Added 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. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H Added CWE CWE-22 Added CWE CWE-59 Added CWE CWE-367 Added Reference https://github.com/onnx/onnx/security/advisories/GHSA-q56x-g2fj-4rj6 Added Reference https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-233-01.json Added Reference https://www.cve.org/CVERecord?id=CVE-2026-49114