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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Thu, 29 Oct 2026 16:15:00 +0000

Type Values Removed Values Added
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.
Title KeePassXC: Out-of-bounds write in browser integration response encryption with oversized database responses
Weaknesses CWE-787
References
Metrics cvssV4_0

{'score': 4.1, 'vector': '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'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-29T16:01:55.635Z

Reserved: 2026-10-28T17:25:37.562Z

Link: CVE-2026-118673

cve-icon Vulnrichment

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cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-29T16:18:03.873

Modified: 2026-10-29T16:29:56.553

Link: CVE-2026-118673

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses