Bug 2523259

Summary: CVE-2026-19499 glibc: Buffer Overflow in strfmon right-justification padding [fedora-all]
Product: [Fedora] Fedora Reporter: Srikanth Balasubramanian <sbalasub>
Component: glibcAssignee: Carlos O'Donell <codonell>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: arjun, codonell, dj, fberat, fweimer, jlaw, josmyers, mcermak, mcoufal, mfabian, pfrankli, sipoyare, skolosov, suraj.ghimire7
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["11a1e9f6-bd1a-4251-bbfa-f712a1a08b3f"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 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: 2523258    

Description Srikanth Balasubramanian 2026-08-25 07:39:02 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.

Summary: Buffer Overflow in strfmon right-justification padding:  <br/>
out-of-bounds write in the caller-supplied output buffer caused by using  <br/>
the post-padding length for the in-place `memmove`.<br/>
Requirements to exploit: A reachable application code path must invoke  <br/>
`strfmon` or `strfmon_l` with right-justified width padding and a  <br/>
destination buffer that is large enough for `__printf_buffer_pad` to  <br/>
succeed but not large enough for the subsequent overlong `memmove`. This  <br/>
may arise through attacker-influenced formatting input or through a fixed  <br/>
susceptible formatting pattern in the calling application.<br/>