CVE-2025-583695.3MediumCWE-400

CVE-2025-58369: fs2: Half-shutdown of socket during TLS handshake may result in spin loop on opposite side

typelevel · fs2

Affected: typelevel fs2 · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days

40th percentile

050100

Higher than 40% of scored CVEs

5.3MediumCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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 products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

typelevel · fs2>= 3.0.0-M1, < 3.12.2; >= 3.13.0-M1, < 3.13.0-M7; < 2.5.13

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Uncontrolled Resource Consumption · Denial of Service
Vendor: typelevel
Published: September 2025
Band: Unlikely (under 1%), September 2025

CoverageNo articles yet

No CyberSIXT article names CVE-2025-58369 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.