389 Directory Server PBKDF2SHA256 Timing Attack via NonConstant Memcmp
CVE-2026-15041 Published on July 8, 2026
389-ds-base: 389-ds-base: non-constant-time comparison in pbkdf2-sha256 password verification
A flaw was found in 389 Directory Server. The PBKDF2-SHA256 password verification function uses standard memcmp() for comparing password hashes instead of a constant-time comparison function. A remote attacker could potentially use timing measurements of LDAP bind attempts to infer partial hash information, though practical exploitation is extremely difficult due to PBKDF2 computational overhead.
Vulnerability Analysis
CVE-2026-15041 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
Observable Timing Discrepancy
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not. In security-relevant contexts, even small variations in timing can be exploited by attackers to indirectly infer certain details about the product's internal operations. For example, in some cryptographic algorithms, attackers can use timing differences to infer certain properties about a private key, making the key easier to guess. Timing discrepancies effectively form a timing side channel.
Products Associated with CVE-2026-15041
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