Bug 2494868

Summary: CVE-2026-58010 glib2: buffer over-read in glib/gvariant-serialiser.c via gvs_tuple_is_normal() [fedora-all]
Product: [Fedora] Fedora Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: glib2Assignee: Matthias Clasen <mclasen>
Status: CLOSED WONTFIX QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: gnome-sig, lpavan, mclasen, rhughes, rstrode
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["30401a73-6694-4570-9292-184c82669c4a"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Clone Of: Environment:
Last Closed: 2026-08-12 14:42:41 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: 2492243    

Description Guilherme de Almeida Suckevicz 2026-06-30 12:57:28 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.

gvs_tuple_is_normal() in glib/gvariant-serialiser.c:1253 has an off-by-one error in its alignment padding check. When checking whether padding bytes are zero, the bounds check uses > instead of >=, allowing a 1-byte out-of-bounds read when offset == value.size.
Comment 1 lpavan 2026-08-12 14:42:41 UTC 
This was fixed upstream with the following releases:

- 2.86.5
- 2.88.1
- 2.89.0

Given that Fedora currently ships 2.86.5 or later across all releases, I'm going to close this.