CVE-2026-104038

Provides a set of daemons to manage access to remote directories and authentication mechanisms. It provides an NSS and PAM interface toward the system and a pluggable back end system to connect to multiple different account sources. It is also the basis to provide client auditing and policy services for projects like FreeIPA.

Security Fix(es):

A flaw was found in SSSD's NFS idmap plugin. When retrieving cached user or group names, the plugin detects if an entry exceeds the destination buffer size but fails to abort before copying data. A local attacker can trigger this vulnerability by requesting identity lookups that resolve to oversized cached entries, resulting in an out-of-bounds write. This flaw primarily leads to a Denial of Service (DoS) by crashing the identity mapping service, and may also corrupt adjacent process memory.(CVE-2026-104036)

A flaw was found in sssd. A remote attacker can cause a denial of service (DoS) by submitting a certificate that lacks an expected Security Identifier (SID) extension. In deployments configured with SID-based certificate mapping rules, the service fails to verify the presence of the extension before processing it, causing the process to crash during authentication or lookup operations.(CVE-2026-104038)

Provides a set of daemons to manage access to remote directories and authentication mechanisms. It provides an NSS and PAM interface toward the system and a pluggable back end system to connect to multiple different account sources. It is also the basis to provide client auditing and policy services for projects like FreeIPA.

Security Fix(es):

A flaw was found in SSSD's NFS idmap plugin. When retrieving cached user or group names, the plugin detects if an entry exceeds the destination buffer size but fails to abort before copying data. A local attacker can trigger this vulnerability by requesting identity lookups that resolve to oversized cached entries, resulting in an out-of-bounds write. This flaw primarily leads to a Denial of Service (DoS) by crashing the identity mapping service, and may also corrupt adjacent process memory.(CVE-2026-104036)

A flaw was found in sssd. A remote attacker can cause a denial of service (DoS) by submitting a certificate that lacks an expected Security Identifier (SID) extension. In deployments configured with SID-based certificate mapping rules, the service fails to verify the presence of the extension before processing it, causing the process to crash during authentication or lookup operations.(CVE-2026-104038)

A flaw was found in sssd. A remote attacker can cause a denial of service (DoS) by submitting a certificate that lacks an expected Security Identifier (SID) extension. In deployments configured with SID-based certificate mapping rules, the service fails to verify the presence of the extension before processing it, causing the process to crash during authentication or lookup operations.

This update for sssd fixes the following issues:

• CVE-2026-12610: cancelled or completed PAM request while the asynchronous child process is still running can lead to a use-after-free (bsc#1269807).
• CVE-2026-68742: unvalidated address lengths in NSS responder packet parsing can cause a heap out-of-bounds read (bsc#1273922).
• CVE-2026-68743: oversized length parameters in authentication requests can cause heap out-of-bounds reads (bsc#1273925).
• CVE-2026-68744: unshrunk packet allocations during group resolution can allow uninitialized heap memory disclosure (bsc#1273924).
• CVE-2026-90462: Fail-open in LDAP ppolicy access check allows continued authorization (bsc#1282584).
• CVE-2026-90463: out-of-bounds read in the NSS service request parsers (bsc#1280360).
• CVE-2026-90994: out-of-bounds read in PAM v1 parser (bsc#1280361).
• CVE-2026-90995: NULL pointer dereference in PAM responder (bsc#1280362).
• CVE-2026-90996: zero-length request body underflow in the NSS responder (bsc#1280363).
• CVE-2026-92821: access control bypass due to premature LDAP access rule evaluation (bsc#1284326).
• CVE-2026-104029: denial of service due to out-of-bounds read in autofs responder (bsc#1284314).
• CVE-2026-104031: denial of service via memory exhaustion in autofs responder (bsc#1284316).
• CVE-2026-104033: access control bypass due to improper LDAP shadow expiration check (bsc#1284318).
• CVE-2026-104036: denial of service due to out-of-bounds write in NFS idmap plugin (bsc#1284321).
• CVE-2026-104037: denial of service due to packet length underflow in autofs responder (bsc#1284322).
• CVE-2026-104038: denial of service via missing SID extension in certificate mapping (bsc#1284323).
• CVE-2026-104039: denial of service due to stale connection state reuse in PAM GSSAPI responder (bsc#1284324).
• CVE-2026-104043: Denial of Service via undersized packet parsing in NSS responder (bsc#1284266).
• CVE-2026-104045: denial of service via race condition in autofs responder (bsc#1284470).