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GHSA-9mj6-hxhv-w67j

HIGH

jose2go is vulnerable to a JWT bomb attack through its decode function

Also known asCVE-2025-63811GO-2025-4123
Published
Nov 12, 2025
Updated
Feb 4, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk14th percentile+0.21%
0.00%0.25%0.49%0.74%0.0%0.2%Dec 25Apr 26Jun 26

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

1 pkg affected
🐹github.com/dvsekhvalnov/jose2go

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

An issue was discovered in dvsekhvalnov jose2go 1.5.0 thru 1.7.0 allowing an attacker to cause a Denial-of-Service (DoS) via crafted JSON Web Encryption (JWE) token with an exceptionally high compression ratio.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/dvsekhvalnov/jose2goall versions1.7.0

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/dvsekhvalnov/jose2go. 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.

  2. Fix

    Update github.com/dvsekhvalnov/jose2go to 1.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9mj6-hxhv-w67j is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-9mj6-hxhv-w67j 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-9mj6-hxhv-w67j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

An issue was discovered in dvsekhvalnov jose2go 1.5.0 thru 1.7.0 allowing an attacker to cause a Denial-of-Service (DoS) via crafted JSON Web Encryption (JWE) token with an exceptionally high compression ratio.
O3 Security · Impact-Aware SCA

Is GHSA-9mj6-hxhv-w67j in your dependencies?

O3 detects GHSA-9mj6-hxhv-w67j across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.