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OpenAdvisories
Medium · 5.3 CVE-2025-58369 EUVD-2025-27048GHSA-rrw2-px9j-qffj

fs2: Half-shutdown of socket during TLS handshake may result in spin loop on opposite side

Published Sep 5, 2025 · Updated Nov 7, 2025 · Assigned by GitHub_M

Description

fs2 is a compositional, streaming I/O library for Scala. Versions up to and including 2.5.12, 3.0.0-M1 through 3.12.2, and 3.13.0-M1 through 3.13.0-M6 are vulnerable to denial of service attacks though TLS sessions using fs2-io on the JVM using the fs2.io.net.tls package. When establishing a TLS session, if one side of the connection shuts down `write` while the peer side is awaiting more data to progress the TLS handshake, the peer side will spin loop on the socket read, fully utilizing a CPU. The CPU is consumed until the overall connection is closed, potentially shutting down a fs2-io powered server. This issue is fixed in versions 2.5.13, 3.12.1, and 3.13.0-M7.

Affected products

VendorProductAffectedFixed
typelevel fs2 >= 3.0.0-M1, < 3.12.2, >= 3.13.0-M1, < 3.13.0-M7, < 2.5.13 —

Affected packages

EcosystemPackageAffectedFixedRecord
Maven co.fs2:fs2-io_0.26 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_0.27 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.11 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.12 >= 3.0.0-M1, < 3.12.2 3.12.2 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.12 >= 3.13.0-M1, < 3.13.0-M7 3.13.0-M7 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.12 < 2.5.13 2.5.13 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.12.0-M4 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.12.0-M5 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.12.0-RC1 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.12.0-RC2 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.13 >= 3.0.0-M1, < 3.12.2 3.12.2 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.13 >= 3.13.0-M1, < 3.13.0-M7 3.13.0-M7 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.13 < 2.5.13 2.5.13 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_2.13.0-M5 all versions — GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_3 >= 3.0.0-M1, < 3.12.2 3.12.2 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_3 >= 3.13.0-M1, < 3.13.0-M7 3.13.0-M7 GHSA-rrw2-px9j-qffj
Maven co.fs2:fs2-io_3 < 2.5.13 2.5.13 GHSA-rrw2-px9j-qffj

References