CVE-2026-68744

A flaw was found in SSSD. The sss_nss_protocol_fill_initgr() function in the NSS responder pre-allocates reply space for all group entries but does not shrink the packet when groups are skipped, causing uninitialized heap bytes to be transmitted to the client. A local attacker can exploit this to disclose cached directory data and heap layout information from the sssd_nss process.

This issue can only be triggered by a local attacker who can connect to the SSSD NSS responder unix socket. The disclosed data is limited to directory-level information and process heap layout from the sssd_nss process. Credentials, hashes, and tickets reside in separate sssd_pam and sssd_be processes and are not exposed by this flaw. Much of the directory data may already be obtainable via legitimate NSS queries depending on the deployment. The primary security concern is disclosure of heap pointers that could assist ASLR bypass if chained with a separate memory-corruption vulnerability.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.