CVE-2023-49290: 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 J...

Description

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.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

0.72%

49.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Lestrrat-Go	Jwx	< 1.2.27
Lestrrat-Go	Jwx	>= 2.0.0, < 2.0.18

References

https://github.com/lestrrat-go/jwx/commit/64f2a229b8e18605f47361d292b526bdc4aee01cPatch
https://github.com/lestrrat-go/jwx/security/advisories/GHSA-7f9x-gw85-8grfExploit, Vendor Advisory
https://github.com/lestrrat-go/jwx/commit/64f2a229b8e18605f47361d292b526bdc4aee01cPatch
https://github.com/lestrrat-go/jwx/security/advisories/GHSA-7f9x-gw85-8grfExploit, Vendor Advisory

Timeline

Published: Dec 5, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-49290?

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.

How severe is CVE-2023-49290?

CVE-2023-49290 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.72% probability of exploitation in the next 30 days.

How do I fix CVE-2023-49290?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.