CVE-2026-90996

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, specifically within the PAM (Pluggable Authentication Modules) responder's protocol v1 parser, pam_parse_in_data(). A local client with access to the PAM responder's UNIX socket can exploit this by negotiating protocol v1 and sending an empty or truncated PAM request body. This can trigger an out-of-bounds read, potentially causing the PAM responder to terminate or restart, leading to a local denial of service.(CVE-2026-90994)

A flaw was found in SSSD (System Security Services Daemon). A local attacker with privileges to connect to the PAM (Pluggable Authentication Modules) responder socket can send a specially crafted protocol request. If the pam_app_services configuration is enabled and the service item is omitted from the request, a NULL pointer dereference can occur. This vulnerability leads to a denial of service, causing the PAM responder to crash and disrupt authentication services.(CVE-2026-90995)

A flaw was found in sssd. A local unprivileged user could send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder. This could lead to a denial-of-service condition, causing the NSS responder to become unstable or terminate. This vulnerability affects the availability of the system responder.(CVE-2026-90996)

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, specifically within the PAM (Pluggable Authentication Modules) responder's protocol v1 parser, pam_parse_in_data(). A local client with access to the PAM responder's UNIX socket can exploit this by negotiating protocol v1 and sending an empty or truncated PAM request body. This can trigger an out-of-bounds read, potentially causing the PAM responder to terminate or restart, leading to a local denial of service.(CVE-2026-90994)

A flaw was found in SSSD (System Security Services Daemon). A local attacker with privileges to connect to the PAM (Pluggable Authentication Modules) responder socket can send a specially crafted protocol request. If the pam_app_services configuration is enabled and the service item is omitted from the request, a NULL pointer dereference can occur. This vulnerability leads to a denial of service, causing the PAM responder to crash and disrupt authentication services.(CVE-2026-90995)

A flaw was found in sssd. A local unprivileged user could send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder. This could lead to a denial-of-service condition, causing the NSS responder to become unstable or terminate. This vulnerability affects the availability of the system responder.(CVE-2026-90996)

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, specifically within the PAM (Pluggable Authentication Modules) responder's protocol v1 parser, pam_parse_in_data(). A local client with access to the PAM responder's UNIX socket can exploit this by negotiating protocol v1 and sending an empty or truncated PAM request body. This can trigger an out-of-bounds read, potentially causing the PAM responder to terminate or restart, leading to a local denial of service.(CVE-2026-90994)

A flaw was found in SSSD (System Security Services Daemon). A local attacker with privileges to connect to the PAM (Pluggable Authentication Modules) responder socket can send a specially crafted protocol request. If the pam_app_services configuration is enabled and the service item is omitted from the request, a NULL pointer dereference can occur. This vulnerability leads to a denial of service, causing the PAM responder to crash and disrupt authentication services.(CVE-2026-90995)

A flaw was found in sssd. A local unprivileged user could send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder. This could lead to a denial-of-service condition, causing the NSS responder to become unstable or terminate. This vulnerability affects the availability of the system responder.(CVE-2026-90996)

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, specifically within the PAM (Pluggable Authentication Modules) responder's protocol v1 parser, pam_parse_in_data(). A local client with access to the PAM responder's UNIX socket can exploit this by negotiating protocol v1 and sending an empty or truncated PAM request body. This can trigger an out-of-bounds read, potentially causing the PAM responder to terminate or restart, leading to a local denial of service.(CVE-2026-90994)

A flaw was found in SSSD (System Security Services Daemon). A local attacker with privileges to connect to the PAM (Pluggable Authentication Modules) responder socket can send a specially crafted protocol request. If the pam_app_services configuration is enabled and the service item is omitted from the request, a NULL pointer dereference can occur. This vulnerability leads to a denial of service, causing the PAM responder to crash and disrupt authentication services.(CVE-2026-90995)

A flaw was found in sssd. A local unprivileged user could send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder. This could lead to a denial-of-service condition, causing the NSS responder to become unstable or terminate. This vulnerability affects the availability of the system responder.(CVE-2026-90996)

A flaw was found in sssd. A local unprivileged user could send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder. This could lead to a denial-of-service condition, causing the NSS responder to become unstable or terminate. This vulnerability affects the availability of the system responder.

• CVE-2026-90462: deny access in sdap_access_ppolicy_step_done() when the LDAP ppolicy user search returns zero entries, instead of returning success and caching an allow decision
• CVE-2026-90996: reject an empty request body in the NSS responder request parsers before body[blen - 1] is read

• CVE-2026-90462: deny access and cache the deny decision when the LDAP ppolicy access check lookup returns zero results, fixing a fail-open that let deleted or deprovisioned users keep passing access checks
• CVE-2026-90996: reject header-only requests with an empty body in the NSS responder parsers, preventing a size_t underflow on body[blen - 1] access that could crash the responder
• CVE-2026-104045: skip reparenting the autofs enumeration context to the maps table when its key was orphaned during the async request, fixing a memory leak in the autofs responder

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).