{"id":"CVE-2025-58369","title":"fs2 is a compositional, streaming I/O library for Scala","summary":"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 JV…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-400"],"published":"2025-09-05","updated":"2026-10-01","sourceUpdated":"2026-10-01T16:10:00.257","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-58369","references":[{"url":"https://github.com/typelevel/fs2/commit/46e2dc3abf994dcf3d0b804b2ddb3c10c04d4976","label":"security-advisories@github.com"},{"url":"https://github.com/typelevel/fs2/commit/5c6c4c6c1ef330f7e6b53661ecc63d5f5ba8885c","label":"security-advisories@github.com"},{"url":"https://github.com/typelevel/fs2/commit/edf0c4f2e660360d1c1a8c5377ce32294de89238","label":"security-advisories@github.com"},{"url":"https://github.com/typelevel/fs2/issues/3590","label":"security-advisories@github.com"},{"url":"https://github.com/typelevel/fs2/releases/tag/v3.12.2","label":"security-advisories@github.com"},{"url":"https://github.com/typelevel/fs2/releases/tag/v3.13.0-M7","label":"security-advisories@github.com"},{"url":"https://github.com/typelevel/fs2/security/advisories/GHSA-rrw2-px9j-qffj","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00448,"epssPercentile":0.38782,"ingestedAt":"2026-10-01T18:55:42.283Z","slug":"CVE-2025-58369","body":"## Overview\n\nfs2 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}