CVE-2026-118673: Memory Corruption

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.

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Weakness Type (CWE)

CWE-787 Out-of-bounds Write

References

Other References

https://github.com/keepassxreboot/keepassxc/commit/80e68bb4e8b89e383dd96b1bf5de169ca61367aa https://github.com/keepassxreboot/keepassxc/pull/13679 https://github.com/keepassxreboot/keepassxc/releases/tag/2.8.0 https://github.com/keepassxreboot/keepassxc/security/advisories/GHSA-3448-gh8j-3227

Frequently Asked Questions

What is 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::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.

How do I check if I'm vulnerable to CVE-2026-118673? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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