---
id: CVE-2026-91926
title: A flaw was found in gss-ntlmssp
summary: >-
  A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info
  parser when a crafted NTLM CHALLENGE message contains duplicated string-valued
  AV_PAIR entries. The parser allocates memory for each string value but does
  not …
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-401
vendor: Red Hat
product: gssntlmssp
affected:
  - gssntlmssp (all versions)
published: '2026-09-15'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T15:16:57.033'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91926'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91926'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533698'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91926.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91926'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91926'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-17T14:24:14.247594Z'
epss: 0.00371
epssPercentile: 0.28322
ingestedAt: '2026-09-15T12:36:50.172Z'
---

## Overview

A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AV_PAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AV_PAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 8 · no fix planned: Red Hat Enterprise Linux 8 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91926.json)