CVE-2026-118673
KeePassXC: Out-of-bounds write in browser integration response encryption with oversized database responses
- State
- Published
- Severity
- 4.1 Medium
- Published
- Oct 29, 2026
- Updated
- Oct 29, 2026
- Reserved
- Oct 28, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 4.1 Medium | 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 | GitHub_M |
Weaknesses
- CWE-787 Out-of-bounds Write
Affected Products
| Product | Versions |
|---|---|
keepassxckeepassxreboot |
|
References
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