# CVE-2025-63811: jose2go is vulnerable to a JWT bomb attack through its decode function

> An attacker can cause a Denial-of-Service in the jose2go library by sending a crafted JWE token with a high compression ratio.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Nov 2025
- **Updated:** 13 Nov 2025
- **Also known as:** CLEANSTART-2026-TQ82043, DEBIAN-CVE-2025-63811, GHSA-9mj6-hxhv-w67j, GO-2025-4123, MINI-25jm-p522-2j6c, MINI-8g87-g6cg-gcp9, MINI-cr28-f2fq-g5rm, MINI-fmp4-h377-96r5, MINI-g6m5-q3xx-xc38, MINI-mx8p-823q-8rmg, MINI-p9c7-p4xh-r9vm, MINI-q5fh-6hj2-7gq8, MINI-r72j-m978-rcq4, MINI-vrhr-63p3-pw2q, MINI-x2gf-xhqm-fqmc, UBUNTU-CVE-2025-63811

## What is CVE-2025-63811?

CVE-2025-63811 is a high-severity denial of service vulnerability in n/a, published on 12 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2025-63811?

3 open source packages ship an affected version, including github.com/dvsekhvalnov/jose2go. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/dvsekhvalnov/jose2go` | Go | All versions | 1.7.0 |
| `github.com/dvsekhvalnov/jose2go` | Go | All versions | 1.7.0 |
| `github.com/dvsekhvalnov/jose2go` | Go | All versions | 1.7.0 |

Products: Dvsekhvalnov Jose2go.

## How do I fix CVE-2025-63811?

Upgrade github.com/dvsekhvalnov/jose2go to 1.7.0 or later.

## Is CVE-2025-63811 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-63811 exists.

## Other vulnerabilities in n/a

- [CVE-2023-50658](https://insights.sbomify.com/CVE-2023-50658/): jose2go vulnerable to denial of service via large p2c value (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-63811 and fix it if it is affected.

What it is: CVE-2025-63811 is a high-severity denial of service vulnerability in n/a, published on 12 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-63811 exists.

Affected packages and fixed versions:
- github.com/dvsekhvalnov/jose2go (Go): affected all versions; fixed in 1.7.0
- github.com/dvsekhvalnov/jose2go (Go): affected all versions; fixed in 1.7.0
- github.com/dvsekhvalnov/jose2go (Go): affected all versions; fixed in 1.7.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-63811/ (Markdown: https://insights.sbomify.com/CVE-2025-63811/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-63811
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-63811
- OSV: https://osv.dev/vulnerability/CVE-2025-63811

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-63811/
Summaries are generated and may contain mistakes; the official description above is the record.