Eglibc: Initializing the DNS stub resolver from an /etc/resolv.conf file, or a LOCALDOMAIN environment variable, whose
Affects eglibcSource GCVE Database
Not known to be exploited · CVSS 5.3 Medium.
Data as of 9 Nov 2026, 14:21 UTC
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 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 9 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro 20.04 LTSglibcpkg:deb/ubuntu/glibc?arch=source&distro=esm-infra/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSglibcpkg:deb/ubuntu/glibc?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in– |
Ubuntu Pro 16.04 LTSglibcpkg:deb/ubuntu/glibc?arch=source&distro=esm-infra/xenialOther threats | Affected
| Fixed in– |
Ubuntu Pro 14.04 LTSeglibcpkg:deb/ubuntu/eglibc?arch=source&distro=esm-infra-legacy/trustyOther 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
Until a fix is available, mitigating exposure involves restricting untrusted local network access to DHCP or VPN services that can influence /etc/resolv.conf or LOCALDOMAIN settings. Monitoring and validating domain search list lengths in network configuration may reduce risk.
Description
A vulnerability in eglibc versions 2.17-2.19 (Ubuntu package variants) causes an assertion failure and process abort when the DNS stub resolver initializes from an /etc/resolv.conf file or LOCALDOMAIN environment variable containing a search domain of roughly 200 characters or more. This occurs due to improper handling of truncated search lists in the fixed-size _res.defdname buffer. Processes that perform DNS resolution via the library are affected, including those that reload /etc/resolv.conf dynamically. An attacker on the local network may trigger this without privileges by influencing DHCP or VPN-provided domain search lists.