CVE-2026-86776

Deferred Deferred - Pending Action

Memory Exhaustion in KeePass Due to Unbounded Header Field Allocation

Publication date: 2026-09-09

Last updated on: 2026-09-10

Assigner: VulnCheck

Description

KeePass versions 2.35 through 2.61.1 fail to validate KDBX header field sizes before memory allocation in the ReadHeaderField function. Attackers can craft a malicious KDBX file declaring excessive header field lengths to trigger allocation of gigabytes of memory, causing the application to consume resources and terminate.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-09

Last Modified

2026-09-10

Generated

2026-09-29

AI Q&A

2026-09-09

EPSS Evaluated

2026-09-27

NVD

CVE-2026-86776

EUVD

EUVD-2026-74788

Affected Vendors & Products

Vendor	Product	Version / Range
dominick_reichl	keepass	From 2.35 (inc) to 2.61.1 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-789	The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.

Attack-Flow Graph

Executive Summary

CVE-2026-86776 is a memory exhaustion vulnerability in KeePass versions 2.35 through 2.61.1. It occurs because the application fails to validate KDBX header field sizes before memory allocation in the ReadHeaderField function. Attackers can exploit this by creating malicious KDBX files with abnormally large header fields, forcing KeePass to allocate excessive memory and crash.

Detection Guidance

Detecting this vulnerability requires monitoring KeePass application behavior when opening KDBX files. Watch for excessive memory usage or crashes when processing files. Use system monitoring tools like 'top' or 'htop' to observe memory consumption during KeePass operations. Check KeePass logs for errors related to memory allocation failures.

Impact Analysis

This vulnerability could cause KeePass to consume excessive system resources, leading to application crashes or system slowdowns. Users opening a malicious KDBX file may experience denial of service, losing access to their stored passwords until the application is restarted.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it primarily causes resource exhaustion in KeePass rather than data breaches or unauthorized access. However, organizations using vulnerable KeePass versions may face operational disruptions that could indirectly impact compliance if critical password management functions are interrupted.

Mitigation Strategies

Immediately update KeePass to the latest version beyond 2.61.1. Avoid opening untrusted KDBX files until patched. Implement file integrity checks for KDBX files. Monitor system resources during KeePass usage. Consider disabling KeePass until updates are applied.

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