{"id":"CVE-2026-118673","title":"KeePassXC: Out-of-bounds write in browser integration response encryption with oversized database responses","summary":"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 fi…","severity":"medium","cvss":4.1,"cvssVector":"CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cvssSource":"cna","cwe":["CWE-787"],"vendor":"keepassxreboot","product":"keepassxc","affected":["keepassxc >= 2.3.0, < 2.8.0"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-03T16:30:40.960267Z"},"exploitAvailable":true,"published":"2026-10-29","updated":"2026-11-03","sourceUpdated":"2026-11-03T16:32:32.671Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-118673","references":[{"url":"https://github.com/keepassxreboot/keepassxc/security/advisories/GHSA-3448-gh8j-3227","label":"https://github.com/keepassxreboot/keepassxc/security/advisories/GHSA-3448-gh8j-3227"},{"url":"https://github.com/keepassxreboot/keepassxc/pull/13679","label":"https://github.com/keepassxreboot/keepassxc/pull/13679"},{"url":"https://github.com/keepassxreboot/keepassxc/commit/80e68bb4e8b89e383dd96b1bf5de169ca61367aa","label":"https://github.com/keepassxreboot/keepassxc/commit/80e68bb4e8b89e383dd96b1bf5de169ca61367aa"},{"url":"https://github.com/keepassxreboot/keepassxc/releases/tag/2.8.0","label":"https://github.com/keepassxreboot/keepassxc/releases/tag/2.8.0"}],"tags":["cve.org","exploit-available"],"epss":0.00115,"epssPercentile":0.01554,"ingestedAt":"2026-11-01T21:01:32.726Z","slug":"CVE-2026-118673","body":"## Overview\n\nKeePassXC 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.\n\n## Affected\n\n- `keepassxc >= 2.3.0, < 2.8.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":35,"depthScoreParts":{"impact":22.5,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":233720,"id":"CVE-2026-118673","ts":1793910826093,"field":"exploit_available","old":"false","new":"true"}]}