There are 5 open security issues in trixie.
4 important issues:
- CVE-2026-90463:
A flaw was found in the sssd NSS responder. This input validation vulnerability allows a local attacker, by sending specially crafted service lookup requests to the NSS responder's UNIX socket, to cause an out-of-bounds read. This out-of-bounds read may lead to a denial of service (DoS) by crashing the NSS responder process. While unprivileged local clients can typically reach the socket, there is no evidence of privilege escalation or reliable data disclosure.
- CVE-2026-90994:
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-2026-90995:
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-2026-90996:
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.
1 issue left for the package maintainer to handle:
- CVE-2026-87853:
(needs triaging)
A flaw was found in SSSD's IdP authentication provider. The eval_access_token_buf() function compares the OIDC subject identifier using strncmp() with the authenticated user's identifier length, performing a prefix comparison instead of an exact match. An attacker whose IdP identifier is a strict prefix of a target user's identifier can authenticate as the target user.
You can find information about how to handle this issue in the security team's documentation.
8 issues that should be fixed with the next stable update:
- CVE-2026-6245:
A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).
- CVE-2025-11561:
A flaw was found in the integration of Active Directory and the System Security Services Daemon (SSSD) on Linux systems. In default configurations, the Kerberos local authentication plugin (sssd_krb5_localauth_plugin) is enabled, but a fallback to the an2ln plugin is possible. This fallback allows an attacker with permission to modify certain AD attributes (such as userPrincipalName or samAccountName) to impersonate privileged users, potentially resulting in unauthorized access or privilege escalation on domain-joined Linux hosts.
- CVE-2026-12610:
A flaw was found in sssd. When authenticating with a YubiKey, the SSSD PAM responder can crash due to a use-after-free vulnerability, where a memory pointer is incorrectly handled. A local attacker could exploit this flaw by manipulating smartcard or YubiKey contents, leading to a denial of service that disrupts authentication. This vulnerability also presents a potential for privilege escalation, although it is difficult to exploit.
- CVE-2026-14474:
A flaw was found in SSSD's LDAP sudo provider. When the ldap_sudo_search_base option is not explicitly configured, SSSD searches the entire LDAP directory tree for sudoRole objects. An authenticated attacker with write access to any subtree can inject a sudoRole object granting root-level sudo privileges on all SSSD-enrolled hosts.
- CVE-2026-14476:
A path traversal flaw was found in SSSD's AD GPO provider. The ad_gpo_extract_smb_components() function does not sanitize .. sequences in the gPCFileSysPath LDAP attribute, allowing an attacker with AD GPO management access to write files outside the GPO cache directory as root. On default RHEL configurations with SELinux enforcing, this can be used to inject Kerberos configuration leading to authentication bypass.
- CVE-2026-68742:
A flaw was found in SSSD. The sss_nss_protocol_parse_addr() function in the NSS responder does not validate the addrlen field against the remaining packet body size. A local attacker can exploit this via a crafted GETHOSTBYADDR request to the NSS responder socket, causing an out-of-bounds read and process crash, resulting in a denial of service.
- CVE-2026-68743:
A flaw was found in SSSD. The extract_authtok_v1() function in the PAM responder does not validate the auth_token_length field against the remaining buffer size before processing. A local attacker can exploit this via a crafted protocol v1 request to the PAM responder socket, causing an out-of-bounds read and process crash, resulting in a denial of service.
- 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.
![[bug history graph]](https://qa.debian.org/data/bts/graphs/s/sssd.png){kind=link}