# CVE-2026-24881: Gpg4win: Stack-based Buffer Overflow

CVE-2026-24881 is fixed in Gpg4win on 1 platform by Gpg4win 5.0.1 (version 5.0.1), released January 27, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2026-24881
- Priority: Urgent
- CVSS: 9.8
- EPSS: 0.0181
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jan 27, 2026
- Weakness: CWE-121: Stack-based Buffer Overflow
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-24881

## Description

In GnuPG before 2.5.17, a crafted CMS (S/MIME) EnvelopedData message carrying an oversized wrapped session key can cause a stack-based buffer overflow in gpg-agent during PKDECRYPT--kem=CMS handling. This can easily be leveraged for denial of service; however, there is also memory corruption that could lead to remote code execution.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | Gpg4win | 5.0.1 | [Gpg4win 5.0.1](https://patchblox.com/security/data/fix/windows-app/gnupg.gpg4win-5.0.1.md) | Jan 27, 2026 |

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Data as of 2026-11-10T07:50:38Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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