KeePassXC is a cross-platform community-driven port of the Windows application KeePass Password Safe.
CVE-2026-118673
KeePassXC is a cross-platform community-driven port of the Windows application KeePass Password Safe. From 2.3.0 until 2.8.0, KeePassXC browser integration encrypts authorized responses in src/browser/BrowserMessageBuilder.cpp using a fixed 1 MiB output vector even though Botan::Sodium::cryptoboxeasy() writes the plaintext length plus cryptoboxMACBYTES. A browser-protocol client that can access the per-user IPC endpoint, has a valid database association, and causes an unlocked database to generate and encrypt a sufficiently large authorized response can trigger a sequential out-of-bounds write before any response is delivered. This issue is fixed in version 2.8.0.
Assessment
- CVSS
- 4.1 (v4.0)
- Severity
- Medium
- EPSS
- 0.12% chance of exploitation in the next 30 days
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 29 October 2026
- Last updated
- 3 November 2026
- Affected
- keepassxreboot · KeePassXC
- Assigner
- GitHub_M
CVSS vectorCVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
At the source
References
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