Red Hat Security Advisory: glibc security update
Affects Red Hat glibcSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 3 Nov 2026, 20:59 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| The GNU C Libraryglibc | Affected
| Fixed in– |
Debiandebian/glibcpkg:deb/debian/glibcOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released updated glibc packages for Red Hat Enterprise Linux 8.4 Extended Life Cycle and related variants to address this vulnerability. Users should apply the official Red Hat security update as described in the advisory RHSA-2026:36643 and the referenced article https://access.redhat.com/articles/11258. Applying this update will remediate the vulnerability. No additional mitigation steps are indicated by the vendor.
Description
A heap buffer overflow vulnerability exists in the GNU C Library (glibc) when using the scanf function with the %mc format specifier and a large width. This flaw affects the standard C libraries used by multiple programs on Linux systems, potentially leading to memory corruption. Red Hat has issued a security update addressing this issue in glibc packages for Red Hat Enterprise Linux 8.4 variants. The vulnerability is rated as moderate severity by Red Hat Product Security.