GnuPG up to 2.5.16 CMS EnvelopedData Message stack-based overflow

Summaryinfo

A vulnerability, which was classified as critical, has been found in GnuPG up to 2.5.16. This vulnerability affects unknown code of the component CMS EnvelopedData Message Handler. Performing a manipulation results in stack-based overflow. This vulnerability is identified as CVE-2026-24881. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in GnuPG up to 2.5.16. This affects an unknown functionality of the component CMS EnvelopedData Message Handler. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at openwall.com. This vulnerability is uniquely identified as CVE-2026-24881 since 01/27/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 297012 (Linux Distros Unpatched Vulnerability : CVE-2026-24881), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.5.17 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (297012) and CERT Bund (WID-SEC-2026-0231). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Fedora Linux
• SUSE Linux
• Open Source GnuPG
• Open Source Gpg4win

Productinfo

Name

• GnuPG

Version

• 2.5.0
• 2.5.1
• 2.5.2
• 2.5.3
• 2.5.4
• 2.5.5
• 2.5.6
• 2.5.7
• 2.5.8
• 2.5.9
• 2.5.10
• 2.5.11
• 2.5.12
• 2.5.13
• 2.5.14
• 2.5.15
• 2.5.16

License

• open-source

CPE 2.3info

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CPE 2.2info

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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