CVE-2026-86776

KeePass 2.35 through 2.61.1 Memory Exhaustion via KDBX Header Field Size

4.6 Medium

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.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: None
User interaction: Active

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: Low

Exploit likelihood

0.17%Up 0.1 points since Sep 10, 2026

What each source reports

CVE List Score used 4.6

KeePass 2.35 through 2.61.1 Memory Exhaustion via KDBX Header Field Size

Record: CVE-2026-86776
CVSS 4.0: 4.6 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Weakness: CWE-789
Updated: 2026-11-02

EUVDEUVD-2026-74788 4.6

Record: EUVD-2026-74788
CVSS 4.0: 4.6 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-5r36-v86r-vm5x 4.6

KeePass versions 2.35 through 2.61.1 fail to validate KDBX header field sizes before memory...

Record: GHSA-5r36-v86r-vm5x
CVSS 4.0: 4.6 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Weakness: CWE-789
Updated: 2026-11-02

NVD 4.6

Record: CVE-2026-86776
CVSS 4.0: 4.6 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Weakness: CWE-789
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-86776 4.6

Record: DEBIAN-CVE-2026-86776
CVSS 4.0: 4.6 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-86776 4.6

Record: UBUNTU-CVE-2026-86776
CVSS 4.0: 4.6 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`keepass2` Debian:12	All versions, plus listed versions 2.47+dfsg-22.57+dfsg-12.57+dfsg-1~bpo12+12.57+dfsg-22.57+dfsg-32.57+dfsg-42.60+dfsg-1	None known
`keepass2` Debian:13	All versions, plus listed versions 2.57+dfsg-32.57+dfsg-42.60+dfsg-1	None known
`keepass2` Debian:14	All versions, plus listed versions 2.57+dfsg-32.57+dfsg-42.60+dfsg-1	None known
`keepass2` Ubuntu:16.04:LTS	All versions, plus listed versions 2.29+dfsg-12.30+dfsg-12.30+dfsg-22.31+dfsg-12.32+dfsg-1	None known
`keepass2` Ubuntu:18.04:LTS	All versions, plus listed versions 2.36+dfsg-12.37+dfsg-12.38+dfsg-1	None known
`keepass2` Ubuntu:20.04:LTS	All versions, plus listed versions 2.41+dfsg-12.43+dfsg-12.44+dfsg-1	None known
`keepass2` Ubuntu:22.04:LTS	All versions, plus listed versions 2.47+dfsg-2	None known
`keepass2` Ubuntu:24.04:LTS	All versions, plus listed versions 2.47+dfsg-2	None known
`keepass2` Ubuntu:26.10	All versions, plus listed versions 2.60+dfsg-1	None known
`keepass2` Ubuntu:26.04:LTS	All versions, plus listed versions 2.57+dfsg-32.57+dfsg-42.60+dfsg-1	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-86776 is a medium vulnerability (CVSS 4.6) in Keepass, published September 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. No source names a fixed version.