Bug 2521282

Summary:	CVE-2026-77584 tor: Tor: Use-after-free vulnerability via CONFLUX_LINK cell handling [epel-all]
Product:	[Fedora] Fedora EPEL	Reporter:	Vladimir Vasilev <vvasilev>
Component:	tor	Assignee:	Marcel Haerry <mh>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	epel10	CC:	mh, pablo, paul.wouters, rh-bugzilla
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["377649cb-a2e5-4b54-aaf1-9033725ddf0c"]}
Fixed In Version:	tor-0.4.9.14-1.el9 tor-0.4.9.14-1.el10_4	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-10-17 00:41:24 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2520791

Description Vladimir Vasilev 2026-08-22 11:47:19 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams. A malicious client could send a RELAY_COMMAND_BEGIN before the CONFLUX_LINK on the same circuit, attaching an exit stream that would later end up orphan leaving a dangling circuit back-pointer and a use-after-free (UAF) when the circuit is freed. This is TROVE-2026-025.

Comment 1 Fedora Update System 2026-10-08 13:48:23 UTC

FEDORA-EPEL-2026-2cce141a86 (tor-0.4.9.14-1.el9) has been submitted as an update to Fedora EPEL 9.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-2cce141a86

Comment 2 Fedora Update System 2026-10-08 13:48:34 UTC

FEDORA-EPEL-2026-4032d817f5 (tor-0.4.9.14-1.el10_4) has been submitted as an update to Fedora EPEL 10.4.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-4032d817f5

Comment 3 Fedora Update System 2026-10-09 02:26:22 UTC

FEDORA-EPEL-2026-2cce141a86 has been pushed to the Fedora EPEL 9 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-2cce141a86

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-10-09 02:32:58 UTC

FEDORA-EPEL-2026-4032d817f5 has been pushed to the Fedora EPEL 10.4 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-4032d817f5

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-10-17 00:41:24 UTC

FEDORA-EPEL-2026-2cce141a86 (tor-0.4.9.14-1.el9) has been pushed to the Fedora EPEL 9 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 6 Fedora Update System 2026-10-17 01:21:25 UTC

FEDORA-EPEL-2026-4032d817f5 (tor-0.4.9.14-1.el10_4) has been pushed to the Fedora EPEL 10.4 stable repository.
If problem still persists, please make note of it in this bug report.