Linux-PAM through 1.7.2 contains an observable timing discrepancy (CWE-208) in the pam_userdb module's plaintext-password comparison path in modules/pam_userdb/pam_userdb.c that allows a local or network-adjacent attacker able to repeatedly drive authentication through a calling service to recover the plaintext password of a target account by measuring response-timing differences. The comparison uses strncmp() (or strncasecmp() when PAM_ICASE_ARG is set) preceded by a length-equality check, so the time to reject a candidate depends on the index of the first differing byte and on whether the candidate's length matches the stored password, leaking the password length and individual prefix bytes. The vulnerable path is reached when the administrator configures pam_userdb with crypt=none, with an unrecognized crypt method, or without a crypt= argument, causing the module to store and compare credentials in plaintext.

The remote Fedora 43 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-adc8ddbeaa advisory.

    pam_userdb: fix password comparison timing leak

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 host has packages installed that are affected by a vulnerability as referenced in the SUSE- SU-2026:3162-1 advisory.

    This update for pam fixes the following issue

    - CVE-2026-54411: timing discrepancy in the pam_userdb module's plaintext-password comparison     (bsc#1268290).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2026:3163-1 advisory.

    This update for pam fixes the following issue

    - CVE-2026-54411: timing discrepancy in the pam_userdb module's plaintext-password comparison     (bsc#1268290).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES16 / SLES_SAP16 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2026:22639-1 advisory.

    This update for pam fixes the following issue

    - CVE-2026-54411: timing discrepancy in the `pam_userdb` module's plaintext-password comparison     (bsc#1268290).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote openSUSE 16 host has packages installed that are affected by a vulnerability as referenced in the openSUSE- SU-2026:21320-1 advisory.

    This update for pam fixes the following issue

    - CVE-2026-54411: timing discrepancy in the `pam_userdb` module's plaintext-password comparison     (bsc#1268290).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-377015b34b advisory.

    pam_userdb: fix password comparison timing leak

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Linux-PAM through 1.7.2 contains an observable timing discrepancy (CWE-208) in the pam_userdb module's     plaintext-password comparison path in modules/pam_userdb/pam_userdb.c that allows a local or network-     adjacent attacker able to repeatedly drive authentication through a calling service to recover the     plaintext password of a target account by measuring response-timing differences. The comparison uses     strncmp() (or strncasecmp() when PAM_ICASE_ARG is set) preceded by a length-equality check, so the time to     reject a candidate depends on the index of the first differing byte and on whether the candidate's length     matches the stored password, leaking the password length and individual prefix bytes. The vulnerable path     is reached when the administrator configures pam_userdb with crypt=none, with an unrecognized crypt     method, or without a crypt= argument, causing the module to store and compare credentials in plaintext.
    (CVE-2026-54411)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
330012	Fedora 43 : pam (2026-adc8ddbeaa)	Nessus	Fedora Local Security Checks	high
328915	SUSE SLES12 Security Update : pam (SUSE-SU-2026:3162-1)	Nessus	SuSE Local Security Checks	high
328908	SUSE SLED15: pam / pam-32bit / pam-devel / pam-devel-32bit / pam-doc / pam-extra / etc (SUSE-SU-2026:3163-1)	Nessus	SuSE Local Security Checks	high
327565	SUSE SLES16 Security Update : pam (SUSE-SU-2026:22639-1)	Nessus	SuSE Local Security Checks	high
327228	openSUSE 16 Security Update : pam (openSUSE-SU-2026:21320-1)	Nessus	SuSE Local Security Checks	high
326099	Fedora 44 : pam (2026-377015b34b)	Nessus	Fedora Local Security Checks	high
321158	Linux Distros Unpatched Vulnerability : CVE-2026-54411	Nessus	Misc.	high

Detections

Analytics

CVE-2026-54411

high

Tenable Plugins

high

high

high

high

high

high

high