Bug 2511527 - CVE-2026-45809 opensips: denial of service in watcherinfo XML generation from oversized watcher URI [fedora-all]
Summary: CVE-2026-45809 opensips: denial of service in watcherinfo XML generation from...
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: opensips
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Peter Lemenkov
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["4b3b0501-aa53-401c-ac11-6...
Depends On:
Blocks: CVE-2026-45809
TreeView+ depends on / blocked
 
Reported: 2026-08-05 13:34 UTC by Guilherme de Almeida Suckevicz
Modified: 2026-08-05 13:42 UTC (History)
1 user (show)

Fixed In Version: opensips-3.6.7-1.fc43 opensips-3.6.7-1.fc44 opensips-4.0.0-9.fc45
Clone Of:
Environment:
Last Closed: 2026-08-05 13:42:37 UTC
Type: ---
Embargoed:


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Description Guilherme de Almeida Suckevicz 2026-08-05 13:34:11 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.

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions prior to 3.6.6 and 4.0.0-rc1 contain a denial of service vulnerability in the watcherinfo generation functionality. An attacker can create an oversized watcher entry by sending a SUBSCRIBE Event: presence request with a long From URI, and then trigger presence.winfo watcherinfo XML generation for the same presentity. OpenSIPS copies the stored watcher URI into a fixed-size stack buffer, overflowing it and crashing the process. A remote attacker can crash an OpenSIPS worker in deployments that expose handle_subscribe() and allow watcherinfo (presence.winfo) generation. The issue is configuration-dependent because the presence and presence_xml modules must be loaded and SUBSCRIBE routing must be reachable. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.

Comment 1 Peter Lemenkov 2026-08-05 13:42:37 UTC
OpenSIPS in Fedora is not affected — every active branch already carries the fix:

- rawhide/f45: opensips-4.0.0-9.fc45
- f44: opensips-3.6.7-1.fc44 (built 2026-06-24)
- f43: opensips-3.6.7-1.fc43 (built 2026-06-24)

There are no EPEL branches for this package, so the above is the full scope of [fedora-all].

Verified against upstream git rather than the advisory version claims. The fix is c5970d3ee ("presence: fix winfo XML overflow on long URIs"), which drops the fixed 200-byte stack buffer in modules/presence/notify.c and builds the watcher node with xmlNodeSetContentLen() using the URI's actual length instead of strncpy() into that buffer. git tag --contains places it in 3.6.6 and 3.6.7.

For 4.0.0 the fix was confirmed by content — modules/presence/notify.c at tag 4.0.0 uses xmlNodeSetContentLen() and no longer declares the char content[200] buffer.

Closing CURRENTRELEASE.


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