Description
The DNS stub resolver in the GNU C Library (aka glibc or libc6) before version 2.26, when EDNS support is enabled, will solicit large UDP responses from name servers, potentially simplifying off-path DNS spoofing attacks due to IP fragmentation.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | glibc | 2.25-1 | — |
| Debian 13 | glibc | 2.25-1 | — |
| Debian 12 | glibc | 2.25-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | glibc | 2.23-0ubuntu11.3+esm3 | USN-5768-1 |
| Ubuntu Pro 14.04 LTS | eglibc | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | nscd +7 | 2.17-222.el7 | RHSA-2018:0805 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | glibc | 2.22-62.6.2 | SUSE-SU-2018:0451-1 |
| SLES 12 SP2 | glibc | 2.22-62.6.2 | SUSE-SU-2018:0451-1 |
| SLES 12 SP1 | glibc | 2.19-40.16.950 | SUSE-SU-2018:2185-1 |
| SLES 12 | glibc | 2.19-22.27.958 | SUSE-SU-2018:2187-1 |
| SLES 11 SP4 | glibc | 2.11.3-17.110.6.2 | SUSE-SU-2018:0565-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP3 | glibc | 2.11.3-17.110.6.2 | SUSE-SU-2018:0565-1 |
| SLES for SAP 12 SP3 | glibc | 2.22-62.6.2 | SUSE-SU-2018:0451-1 |
| SLES for SAP 12 SP2 | glibc | 2.22-62.6.2 | SUSE-SU-2018:0451-1 |
| SLES for SAP 12 SP1 | glibc | 2.19-40.16.950 | SUSE-SU-2018:2185-1 |
| SLES for SAP 11 SP4 | glibc | 2.11.3-17.110.6.2 | SUSE-SU-2018:0565-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | glibc | 2.11.3-17.110.6.2 | SUSE-SU-2018:0565-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | glibc | 2.34-1.2 | openSUSE-SU-2024:10792-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | nscd +6 | 2.17-222.el7 | ELSA-2018-0805 |
Advisories 8
- RHSA-2018:0805 Red Hat Security Advisory: glibc security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-5768-1 glibc vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- openSUSE-SU-2024:10792-1 glibc-2.34-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2185-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0451-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2187-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0565-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2018-0805 Moderate: glibc security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 16, 2018
References
- https://arxiv.org/pdf/1205.4011.pdf
- 100598 vdb-entry
- https://sourceware.org/bugzilla/show_bug.cgi?id=21361
- RHSA-2018:0805 vendor-advisory