How severe is CVE-2022-31183?

CVE-2022-31183 has a CVSS score of 9.1/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-31183?

CVE-2022-31183 affects the following packages: co.fs2:fs2-io (Maven), co.fs2:fs2-io_2.12 (Maven), co.fs2:fs2-io_3 (Maven), co.fs2:fs2-io_2.13 (Maven), co.fs2:fs2-io_sjs1_2.13 (Maven), co.fs2:fs2-io_sjs1_3 (Maven). Ecosystems affected: Maven.

How do I fix CVE-2022-31183?

Update co.fs2:fs2-io to 3.2.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-31183 is resolved across your whole dependency graph.

How do I detect CVE-2022-31183 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for co.fs2:fs2-io. 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 CVE-2022-31183 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 CVE-2022-31183?

O3 pinpoints whether CVE-2022-31183 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 CVE-2022-31183 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2022-31183, 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 CVE-2022-31183?

CVE-2022-31183 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 45th 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.

What type of vulnerability is CVE-2022-31183?

CVE-2022-31183 is classified as CWE-295 (CWE-295). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2022-31183 published, and has it been updated?

CVE-2022-31183 was published on August 1, 2022 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

CVE-2022-31183

CRITICAL

mTLS client verification is skipped in fs2 on Node.js

Also known asGHSA-2cpx-6pqp-wf35

Published

Aug 1, 2022

Updated

Apr 10, 2026

Affected

6 pkgs

Patched

6 / 6

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk45th percentile+0.42%

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

6 pkgs affected

☕co.fs2:fs2-io☕co.fs2:fs2-io_2.12☕co.fs2:fs2-io_3☕co.fs2:fs2-io_2.13☕co.fs2:fs2-io_sjs1_2.13☕co.fs2:fs2-io_sjs1_3

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

Description

fs2 is a compositional, streaming I/O library for Scala. When establishing a server-mode TLSSocket using fs2-io on Node.js, the parameter requestCert = true is ignored, peer certificate verification is skipped, and the connection proceeds. The vulnerability is limited to: 1. fs2-io running on Node.js. The JVM TLS implementation is completely independent. 2. TLSSockets in server-mode. Client-mode TLSSockets are implemented via a different API. 3. mTLS as enabled via requestCert = true in TLSParameters. The default setting is false for server-mode TLSSockets. It was introduced with the initial Node.js implementation of fs2-io in 3.1.0. A patch is released in v3.2.11. The requestCert = true parameter is respected and the peer certificate is verified. If verification fails, a SSLException is raised. If using an unpatched version on Node.js, do not use a server-mode TLSSocket with requestCert = true to establish a mTLS connection.

Affected Packages

6 total 6 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`co.fs2:fs2-io`	≥ 3.1.0&&< 3.2.11	3.2.11
☕Maven	`co.fs2:fs2-io_2.12`	≥ 3.1.0&&< 3.2.11	3.2.11
☕Maven	`co.fs2:fs2-io_3`	≥ 3.1.0&&< 3.2.11	3.2.11
☕Maven	`co.fs2:fs2-io_2.13`	≥ 3.1.0&&< 3.2.11	3.2.11
☕Maven	`co.fs2:fs2-io_sjs1_2.13`	≥ 3.1.0&&< 3.2.11	3.2.11
☕Maven	`co.fs2:fs2-io_sjs1_3`	≥ 3.1.0&&< 3.2.11	3.2.11

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.

fs2 is a compositional, streaming I/O library for Scala. When establishi…

github.comNVDAug 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for co.fs2:fs2-io. 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 co.fs2:fs2-io to 3.2.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-31183 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 CVE-2022-31183 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 CVE-2022-31183. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

fs2 is a compositional, streaming I/O library for Scala. When establishing a server-mode `TLSSocket` using `fs2-io` on Node.js, the parameter `requestCert = true` is ignored, peer certificate verification is skipped, and the connection proceeds. The vulnerability is limited to: 1. `fs2-io` running on Node.js. The JVM TLS implementation is completely independent. 2. `TLSSocket`s in server-mode. Client-mode `TLSSocket`s are implemented via a different API. 3. mTLS as enabled via `requestCert = true` in `TLSParameters`. The default setting is `false` for server-mode `TLSSocket`s. It was introduce

O3 Security · Impact-Aware SCA

Is CVE-2022-31183 in your dependencies?

O3 detects CVE-2022-31183 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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