Bug 2511605

Summary: CVE-2026-18739 popt: Off-by-one in poptStuffArgs [fedora-all]
Product: [Fedora] Fedora Reporter: Charles Timko <ctimko>
Component: poptAssignee: Robert Scheck <redhat-bugzilla>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: low    
Version: 45CC: ffesti, pmatilai, redhat-bugzilla
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---Flags: fedora-admin-xmlrpc: mirror+
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["a75cbec9-7b7d-497f-bfb2-db4c8c4f6964"]}
Fixed In Version: Doc Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2510737    

Description Charles Timko 2026-08-05 15:28:21 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.

Depth check lacks + 1 vs handleAlias; 10th stuff can advance os past optionStack[0..9] into adjacent poptContext fields (e.g. leftovers). Claimed LCE only if host uses corrupted poptGetArg* unsafely.

popt-1.18/src/popt.c:1671

Flow: Host repeatedly calls poptStuffArgs (and/or deep alias nesting) → overflow con->os → corrupt context → later poptGetArg / poptGetArgs / poptPeekArg → only if host sinks that string into exec/system/popen/dlopen (or equivalent).

Analysis has identified that this goes back to the git tag `popt-1_1_1`
Comment 1 Aoife Moloney 2026-08-17 15:47:25 UTC 
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.