fs2-io skips mTLS client verification
Impact
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:
fs2-iorunning on Node.js. The JVM TLS implementation is completely independent.TLSSockets in server-mode. Client-modeTLSSockets are implemented via a different API.- mTLS as enabled via
requestCert = trueinTLSParameters. The default setting isfalsefor server-modeTLSSockets.
It was introduced with the initial Node.js implementation of fs2-io in v3.1.0.
Patches
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.
Workarounds
If using an unpatched version on Node.js, do not use a server-mode TLSSocket with requestCert = true to establish a mTLS connection.
References
- https://github.com/nodejs/node/issues/43994
- https://www.cloudflare.com/learning/access-management/what-is-mutual-tls/
For more information
If you have any questions or comments about this advisory:
- Open an issue.
- Contact the Typelevel Security Team.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | co.fs2:fs2-io | >= 3.1.0, < 3.2.11 | 3.2.11 |
| Java / Kotlin (Maven) | co.fs2:fs2-io_2.12 | >= 3.1.0, < 3.2.11 | 3.2.11 |
| Java / Kotlin (Maven) | co.fs2:fs2-io_2.13 | >= 3.1.0, < 3.2.11 | 3.2.11 |
| Java / Kotlin (Maven) | co.fs2:fs2-io_3 | >= 3.1.0, < 3.2.11 | 3.2.11 |
| Java / Kotlin (Maven) | co.fs2:fs2-io_sjs1_2.13 | >= 3.1.0, < 3.2.11 | 3.2.11 |
| Java / Kotlin (Maven) | co.fs2:fs2-io_sjs1_3 | >= 3.1.0, < 3.2.11 | 3.2.11 |
References
- https://github.com/typelevel/fs2/security/advisories/GHSA-2cpx-6pqp-wf35
- https://nvd.nist.gov/vuln/detail/CVE-2022-31183
- https://github.com/nodejs/node/issues/43994
- https://github.com/typelevel/fs2/commit/19ce392e8093d9571387dbd78e159e655a85aeea
- https://github.com/typelevel/fs2/commit/659824395826a314e0a4331535dbf1ef8bef8207
- https://github.com/typelevel/fs2
- https://github.com/typelevel/fs2/releases/tag/v3.2.11
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-295- Platform
- Java / Kotlin (Maven)
- Package
co.fs2:fs2-io, co.fs2:fs2-io_2.12, co.fs2:fs2-io_2.13- Disclosed
- 29.07.2022
- Updated
- 11.10.2026 12:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-2cpx-6pqp-wf35 - CC BY 4.0
Vulnerability history: co.fs2:fs2-io_2.12
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 07.2022 09.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- Medium 1
Disclosures per year
- 2022: 1
- 2023: 0
- 2024: 0
- 2025: 1
- 2026: 0
-
fs2-io skips mTLS client verification this entry
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