Local Denial of Service Vulnerability in SSSD's PAM Responder
CVE-2026-127101

5.5MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Vendor
CVE Published:
12 November 2026

What is CVE-2026-127101?

A local vulnerability exists in the PAM responder of SSSD, which allows an attacker to initiate an authentication request without prior negotiation of the client protocol version. This flaw causes the responder to dereference a NULL protocol-version pointer, resulting in a crash. Attackers can exploit this vulnerability by repeatedly sending crafted requests, leading to a sustained denial of service and disruption of SSSD-backed authentication services.

References

https://access.redhat.com/security/cve/CVE-2026-127101
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2572592
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
5.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank Priyank Nigam (Microsoft Cloud Security) for reporting this issue.
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