CVE-2023-49290: Lestrrat-Go Jwx

Medium severity, CVSS 5.3. EPSS: 0.7% chance of exploitation in the next 30 days.

lestrrat-go/jwx is a Go module implementing various JWx (JWA/JWE/JWK/JWS/JWT, otherwise known as JOSE) technologies. A p2c parameter set too high in JWE's algorithm PBES2-* could lead to a denial of service. The JWE key management algorithms based on PBKDF2 require a JOSE Header Parameter called p2c (PBES2 Count). This parameter dictates the number of PBKDF2 iterations needed to derive a CEK wrapping key. Its primary purpose is to intentionally slow down the key derivation function, making password brute-force and dictionary attacks more resource- intensive. Therefore, if an attacker sets the p2c parameter in JWE to a very large number, it can cause a lot of computational consumption, resulting in a denial of service. This vulnerability has been addressed in commit `64f2a229b` which has been included in release version 1.2.27 and 2.0.18. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Affected products

• Lestrrat-Go Jwx: before 1.2.27 (fixed in 1.2.27); from 2.0.0, before 2.0.18 (fixed in 2.0.18)

Published 2023-12-05. Last modified 2026-06-17.