GHSA-rrw2-px9j-qffj — medium GitHub Advisory (CVE-2025-58369) in maven/co.fs2:fs2-io

Description

Impact

When establishing a TLS session using fs2-io on the JVM using the fs2.io.net.tls package, 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. This CPU is consumed until the overall connection is closed.

This could be used as a denial of service attack on an fs2-io powered server -- for example, by opening many connections and putting them in a half-shutdown state.

Note: this issue impacts ember backed http4s servers with HTTPS as a result of ember using fs2's TLS support.

Patches

Fixed in fs2 3.12.2 and 3.13.0-M7.

Workarounds

No workarounds.

For more information

If you have any questions or comments about this advisory:

Open an issue.
Contact the Typelevel Security Team.

Basic information

Type: reviewed
Severity: medium
Advisory on GitHub: Open advisory ↗
Repository advisory: Open repository advisory ↗
Source code: Browse source ↗
Published (advisory): 2025-09-05 20:58:23 UTC
Updated: 2025-11-07 12:29:28 UTC
GitHub reviewed: 2025-09-05 20:58:23 UTC
NVD published: 2025-09-05

Score	Percentile
0.20%	41.77%

CVSS Scores

Base score	Version	Severity	Vector
5.3	3.1	—	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

Type	Value
GHSA	GHSA-rrw2-px9j-qffj ↗
CVE	CVE-2025-58369 ↗

CWEs

CWE id	Name
CWE-400	Uncontrolled Resource Consumption

Credits

lukestephenson-zendesk (analyst)

Affected packages (17)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem	Package	Vulnerable range	First patched	Vulnerable functions
maven	co.fs2:fs2-io_2.12	>= 3.13.0-M1, < 3.13.0-M7	3.13.0-M7	—
maven	co.fs2:fs2-io_2.13	>= 3.13.0-M1, < 3.13.0-M7	3.13.0-M7	—
maven	co.fs2:fs2-io_3	>= 3.13.0-M1, < 3.13.0-M7	3.13.0-M7	—
maven	co.fs2:fs2-io_2.12	>= 3.0.0-M1, < 3.12.2	3.12.2	—
maven	co.fs2:fs2-io_2.13	>= 3.0.0-M1, < 3.12.2	3.12.2	—
maven	co.fs2:fs2-io_3	>= 3.0.0-M1, < 3.12.2	3.12.2	—
maven	co.fs2:fs2-io_0.26	< 2.5.13	—	—
maven	co.fs2:fs2-io_0.27	< 2.5.13	—	—
maven	co.fs2:fs2-io_2.11	< 2.5.13	—	—
maven	co.fs2:fs2-io_2.12.0-M4	< 2.5.13	—	—
maven	co.fs2:fs2-io_2.12.0-RC1	< 2.5.13	—	—
maven	co.fs2:fs2-io_2.12.0-M5	< 2.5.13	—	—
maven	co.fs2:fs2-io_2.12.0-RC2	< 2.5.13	—	—
maven	co.fs2:fs2-io_2.13.0-M5	< 2.5.13	—	—
maven	co.fs2:fs2-io_2.12	< 2.5.13	2.5.13	—
maven	co.fs2:fs2-io_2.13	< 2.5.13	2.5.13	—
maven	co.fs2:fs2-io_3	< 2.5.13	2.5.13	—

FS2 half-shutdown of socket during TLS handshake may result in spin loop on opposite side