Bug 2503675 - CVE-2026-59850 libssh: libssh: use-after-free via data callbacks on closed channels [fedora-all]
Summary: CVE-2026-59850 libssh: libssh: use-after-free via data callbacks on closed ch...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: libssh
Version: rawhide
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Andreas Schneider
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["cf52b3f0-2673-4b56-9831-c...
Depends On:
Blocks: CVE-2026-59850
TreeView+ depends on / blocked
 
Reported: 2026-07-21 15:16 UTC by Vladimir Vasilev
Modified: 2026-07-23 01:20 UTC (History)
5 users (show)

Fixed In Version: libssh-0.11.5-1.fc43 libssh-0.12.1-1.fc44
Clone Of:
Environment:
Last Closed: 2026-07-23 01:03:40 UTC
Type: ---
Embargoed:
fedora-admin-xmlrpc: mirror+


Attachments (Terms of Use)

Description Vladimir Vasilev 2026-07-21 15:16:32 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.

A flaw was found in libssh channel data handling. In channel_rcv_data() in src/channels.c, incoming channel DATA messages could still be processed after the channel had already been marked as remotely closed. In SFTP-backed applications and other callback-driven consumers, this creates a path where data callbacks may observe channel-associated state after it has already been torn down or freed, leading to crashes and possible use-after-free conditions.

Comment 1 Fedora Update System 2026-07-22 09:32:55 UTC
FEDORA-2026-0e46c91ccf (libssh-0.12.1-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-0e46c91ccf

Comment 2 Fedora Update System 2026-07-22 09:33:53 UTC
FEDORA-2026-063caa9112 (libssh-0.11.5-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-063caa9112

Comment 3 Fedora Update System 2026-07-23 01:03:40 UTC
FEDORA-2026-063caa9112 (libssh-0.11.5-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 4 Fedora Update System 2026-07-23 01:20:31 UTC
FEDORA-2026-0e46c91ccf (libssh-0.12.1-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.


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