CVE-2026-118673
Description
A flaw was found in KeePassXC. A local user with access to the inter-process communication (IPC) interface and an authorized database association can cause a Denial of Service (DoS) by crashing the application. By prompting an unlocked database to generate and encrypt an excessively large response through the browser integration component, the application triggers an out-of-bounds write beyond the allocated buffer, terminating the process.
Statement
This vulnerability is rated as having Moderate impact because exploitation requires local access alongside multiple prerequisites, including an active and unlocked database session with an already-established browser pairing. Under these conditions, an attacker can only force the KeePassXC process to crash, resulting in a denial of service without compromising data confidentiality or system integrity. Furthermore, the browser integration feature must be actively enabled and configured by the user, limiting exposure in standard deployments.
Mitigation
Upgrade KeePassXC to 2.8.0 or later, which fixes the out-of-bounds write in browser-integration message encryption/decryption (commit 80e68bb, release 2026-10-21). As a workaround, disable browser integration in KeePassXC settings to remove the vulnerable native-messaging/IPC code path.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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