CVE-2023-25565: GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication

Q: How do I fix CVE-2023-25565?

gss-ntlmssp: upgrade to 1.2.0. Exact commands for each OS are on this page.

Q: Is CVE-2023-25565 being exploited?

CVE-2023-25565 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-25565 affect?

CVE-2023-25565 affects gss-ntlmssp. Severity is high (CVSS 7.5). GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, an incorrect free when decoding target information can trigger a denial of service. The error condition incorrectly assumes

Q: How urgent is CVE-2023-25565?

Priority 48/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2023-25565 is a high-severity flaw (CVSS 7.5) affecting gss-ntlmssp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, an incorrect free when decoding target information can trigger a denial of service. The error condition incorrectly assumes the `cb` and `sh` buffers contain a copy of the data that needs to be freed. However, that is not the case. This vulnerability can be triggered via the main `gss_accept_sec_context` entry point. This will like

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-590, CWE-763
Published	2023-02-14
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: gss-ntlmssp project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-02-14 18:15 UTCPublished CVE record published
2026-06-17 05:41 UTCUpdated Record last modified

gss-ntlmssp project gss-ntlmssp UPGRADE

Affected: < 1.2.0

Fixed in: 1.2.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy gss-ntlmssp || rpm -q gss-ntlmssp || gss-ntlmssp --version

2. UPGRADE to 1.2.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade gss-ntlmssp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gss-ntlmssp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-25565?

gss-ntlmssp: upgrade to 1.2.0. Exact commands for each OS are on this page.

Is CVE-2023-25565 being exploited?

CVE-2023-25565 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-25565 affect?

CVE-2023-25565 affects gss-ntlmssp. Severity is high (CVSS 7.5). GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, an incorrect free when decoding target information can trigger a denial of service. The error condition incorrectly assumes

How urgent is CVE-2023-25565?

Priority 48/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2023-25567 HIGH 7.5 UPGRADE GSS-NTLMSSP, a mechglue plugin for the GSSAPI library that implements NTLM authentication, has an out-of-bound
CVE-2023-25566 HIGH 7.5 UPGRADE GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication
CVE-2023-25564 MEDIUM 6.5 UPGRADE GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication
CVE-2023-25563 MEDIUM 5.9 UPGRADE GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication

References

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