CVE-2026-94184

Publication date 21 September 2026

Last updated 11 November 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A stack-based buffer overflow flaw was found in fetchmail when built with NTLM support. A malicious or compromised mail server advertising NTLM authentication can send a crafted Type 2 challenge that causes fetchmail to write past a fixed stack buffer while building the NTLM authenticate response. This may lead to remote code execution depending on stack-frame layout, or to authentication failure or process termination under memory hardening.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
fetchmail	26.10 stonking	Fixed in 6.6.6-1ubuntu0.1
	26.04 LTS resolute	Fixed in 6.6.2-2ubuntu0.1
	24.04 LTS noble	Fixed in 6.4.38-1ubuntu4.2
	22.04 LTS jammy	Fixed in 6.4.27-1ubuntu0.2
	20.04 LTS focal	Fixed in 6.4.2-2ubuntu0.1~esm1
	18.04 LTS bionic	Fixed in 6.3.26-3ubuntu0.1~18.04.1+esm1
	16.04 LTS xenial	Fixed in 6.3.26-2ubuntu0.1~esm1

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Notes

mdeslaur

Because of compiler hardening, in Ubuntu this is only a denial of service.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
fetchmail	Upstream: cb5be5c

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.3 · Medium

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	Low

Scores

Parameter	Value
Base score	5.3 · Medium
Exploitability score	-
Impact score	-