KeePass 2.35 through 2.61.1 Memory Exhaustion via KDBX Header Field Size

Advisories

KeePass 2.35 through 2.61.1 Memory Exhaustion via KDBX Header Field Size

severity: medium
date: 9/9/2026
Affecting: KeePass <= 2.61.1
CVE: CVE-2026-86776
CWE: CWE-789 Memory Allocation with Excessive Size Value
CVSS: 4.6
CVSS V4 Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References: Reporter write-up and proof of concept
https://keepass.info/
KeePass 2.61.1 downloads (including source)
Credit: KSecur1ty
Description: KeePass versions 2.35 through 2.61.1 fail to validate KDBX header field sizes before memory allocation in the ReadHeaderField function. Attackers can craft a malicious KDBX file declaring excessive header field lengths to trigger allocation of gigabytes of memory, causing the application to consume resources and terminate.

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