Red Hat Security Advisory: glibc security update
Affects Red Hat glibcSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Mar 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 30 Oct 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 9 and related variants that address these vulnerabilities. Users should apply the provided security updates as detailed in the Red Hat advisory RHSA-2026:20597. No additional mitigation steps are indicated beyond applying the official patches.
Description
The glibc packages provide the standard C libraries (libc), POSIX thread libraries (libpthread), standard math libraries (libm), and the name service cache daemon (nscd) used by multiple programs on the system. Without these libraries, the Linux system cannot function correctly. Security Fix(es): * glibc: glibc: Incorrect DNS response parsing via crafted DNS server response (CVE-2026-4437) * glibc: glibc: Invalid DNS hostname returned via gethostbyaddr functions (CVE-2026-4438) * glibc: glibc: Denial of Service via iconv() function with specific character sets (CVE-2026-4046) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
References
- access.redhat.com/errata/RHSA-2026:20597 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2449777 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2449783 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2453117 (opens in a new tab)
- issues.redhat.com/browse/RHEL-148252 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_20597.json (opens in a new tab)