CVE-2026-89314: Quadratic-time key_ops duplicate check lets a sub-1 MB JWKS body pin a CPU core for ~15 s
jwkFields.CheckConsistency detected duplicate keyops entries with a pairwise nested loop, making validation cost grow with the square of the entry count. Because the check runs on every JWK and JWKS unmarshal, a modestly sized but hostile JWKS document could occupy a CPU core for many seconds.
Affected Software
Event History
Frequently Asked Questions
What inputs can trigger the excessive CPU use?
A hostile JWK or JWKS document containing a large number of key_ops entries can trigger it. The duplicate check is performed during every JWK and JWKS unmarshal.
Does an attacker need to send a large payload?
No. The issue can be triggered by a JWKS body smaller than 1 MB, while the quadratic duplicate check can occupy a CPU core for roughly 15 seconds.
Who is exposed in practice?
Applications that unmarshal JWK or JWKS data from attacker-controlled or otherwise untrusted sources are exposed to CPU exhaustion. Repeated processing of hostile documents could tie up available CPU capacity.