How severe is GHSA-489j-g2vx-39wf?

GHSA-489j-g2vx-39wf has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-489j-g2vx-39wf?

GHSA-489j-g2vx-39wf affects the following packages: transformers (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-489j-g2vx-39wf?

Update transformers to 4.51.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-489j-g2vx-39wf is resolved across your whole dependency graph.

How do I detect GHSA-489j-g2vx-39wf in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for transformers. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-489j-g2vx-39wf if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-489j-g2vx-39wf?

O3 pinpoints whether GHSA-489j-g2vx-39wf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-489j-g2vx-39wf actively exploited in the wild?

No public exploit code has been indexed for GHSA-489j-g2vx-39wf yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is GHSA-489j-g2vx-39wf?

GHSA-489j-g2vx-39wf is classified as CWE-1333 (CWE-1333). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-489j-g2vx-39wf published, and has it been updated?

GHSA-489j-g2vx-39wf was published on July 7, 2025 and was last updated on July 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

GHSA-489j-g2vx-39wf

MEDIUMFix: huggingface/transformers@0720e20

GHSA-489j-g2vx-39wf is a medium-severity (CVSS 5.3) CWE-1333 vulnerability in transformers. O3 Security confirms whether GHSA-489j-g2vx-39wf is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Transformers vulnerable to ReDoS attack through its SETTING_RE variable

Also known asCVE-2025-3262PYSEC-2026-1979

Published

Jul 7, 2025

Updated

Jul 7, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Real-World Exposure

1 pkg affected

🐍transformers

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the huggingface/transformers repository, specifically in version 4.49.0. The vulnerability is due to inefficient regular expression complexity in the SETTING_RE variable within the transformers/commands/chat.py file. The regex contains repetition groups and non-optimized quantifiers, leading to exponential backtracking when processing 'almost matching' payloads. This can degrade application performance and potentially result in a denial-of-service (DoS) when handling specially crafted input strings. The issue is fixed in version 4.51.0.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`transformers`	≥ 4.49.0&&< 4.51.0	4.51.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for transformers. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update transformers to 4.51.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-489j-g2vx-39wf is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-489j-g2vx-39wf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-489j-g2vx-39wf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the huggingface/transformers repository, specifically in version 4.49.0. The vulnerability is due to inefficient regular expression complexity in the `SETTING_RE` variable within the `transformers/commands/chat.py` file. The regex contains repetition groups and non-optimized quantifiers, leading to exponential backtracking when processing 'almost matching' payloads. This can degrade application performance and potentially result in a denial-of-service (DoS) when handling specially crafted input strings. The issue is

O3 Security · Impact-Aware SCA

Is GHSA-489j-g2vx-39wf in your dependencies?

O3 detects GHSA-489j-g2vx-39wf across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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