# CVE-2025-63811: jose2go DoS — Fixed in 1.7.0

🐹

🐹 Go

Not in CISA KEV

HIGH severity

# CVE-2025-63811 — jose2go

HIGH [Fix: dvsekhvalnov/jose2go@0a0673d](https://github.com/dvsekhvalnov/jose2go/commit/0a0673dd7f2820a446de5b04b9094b2291d77d5d)

CVE-2025-63811 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in github.com/dvsekhvalnov/jose2go. A fix is available for github.com/dvsekhvalnov/jose2go — see the affected versions and patch details below.

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

Also known as[GHSA-9mj6-hxhv-w67j](/vulnerability/GHSA-9mj6-hxhv-w67j)GO-2025-4123

Published

Nov 12, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

## Exploitation Status

### Proof-of-concept exploit code exists

-   CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
-   CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-63811.

## EPSS Exploitation Probability

[via FIRST.org ↗](https://www.first.org/epss/)

0.3%probability of exploitation in next 30 days

Lower Risk+0.03%

Lower risk than most CVEs20th percentile — riskier than 20% of all scored CVEsHighest risk

0.00%0.26%0.52%0.78%0.0%0.3%May 26Aug 26Nov 26

Probability of exploitation in the next 30 days, from [FIRST.org EPSS](https://www.first.org/epss/).

## How urgent is this, really

## Where this sits among everything scored

## Real-World Exposure

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

Ecosystem

Package

Vulnerable range

Fix

🐹Go

`github.com/dvsekhvalnov/jose2go` 

all versions

1.7.0`go get github.com/dvsekhvalnov/jose2go@v1.7.0`

## Affected Products

1 product · 1 configurations

Application

`jose2go`dvsekhvalnov

≥ 1.5.0 && < 1.7.0

range

## 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
    
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 CVE-2025-63811 is resolved across your whole dependency graph.
    
3.  ### Workarounds
    
    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
    

## 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 CVE-2025-63811 in your dependencies?

Find it across Go, including transitive dependencies.

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