CVE-2026-118673 KeePassXC: Out-of-bounds write in browser integration response encryption with oversized database responses
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-118673?
CVE-2026-118673 is a medium-severity vulnerability in keepassxreboot keepassxc, published on 29 Oct 2026.
Official description
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::crypto_box_easy() writes the plaintext length plus crypto_box_MACBYTES. 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.
Weakness: CWE-787
Which versions are affected by CVE-2026-118673?
How do I fix CVE-2026-118673?
No fix has been published for CVE-2026-118673 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-118673 being exploited?
There is no known exploitation of CVE-2026-118673 in the wild and no public exploit code.
Sources
Also known as GHSA-3448-gh8j-3227.