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 7 Extended Lifecycle Support that fix this vulnerability. Users should apply the official security update as detailed in Red Hat advisory RHSA-2026:34211. 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 Red Hat Enterprise Linux 7 Extended Lifecycle Support versions. The vulnerability has been rated as moderate severity by Red Hat Product Security. A security update addressing this issue is available from Red Hat.