Description
Calling tdelete on a sufficiently deep tree in the GNU C Library version 2.1 to 2.44 may write one pointer past the end of an alloca-allocated array on the stack, which may crash the application.
The tdelete implementation keeps an explicit stack of parent nodes for rebalancing, which is grown as needed while descending the tree. Two rebalancing branches push an additional entry without checking the capacity, and write past the array when the stack is exactly full. Triggering this requires a node at a depth of exactly 40 (or 40 plus a multiple of 20), which implies a tree with at least a million nodes, so an attacker must drive a large number of insertions and deletions through an application that uses tsearch and tdelete. The written value is a pointer into a tree node and is not directly attacker controlled. No affected application in common distributions has been identified.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| The GNU C Library | glibc | 2.1 – ≤ 2.44 | — |
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 | 2.43-4 | — |
| Debian 13 | glibc | No fix yet | — |
| Debian 12 | glibc | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | glibc | 2.43-2ubuntu2.4 | USN-8737-1 |
| Ubuntu 24.04 LTS | glibc | 2.39-0ubuntu8.9 | USN-8737-2 |
| Ubuntu 22.04 LTS | glibc | 2.35-0ubuntu3.15 | USN-8737-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | glibc | No fix yet | — |
| Ubuntu Pro 18.04 LTS | glibc | No fix yet | — |
| Ubuntu Pro 16.04 LTS | glibc | No fix yet | — |
| Ubuntu Pro 14.04 LTS | eglibc | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | glibc +220 | 2.39-142.el10_2 | RHSA-2026:76781 |
| RHEL 9 | nscd +214 | 2.34-283.el9_8 | RHSA-2026:79281 |
| RHEL 8 | nscd +213 | 2.28-251.el8_10.48 | RHSA-2026:80798 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | glibc +227 | 2.43-8.2.hum1 | RHSA-2026:59721 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | glibc +220 | 2.39-142.el10_2.alma.1 | ALSA-2026:76781 |
| AlmaLinux 9 | nscd +214 | 2.34-283.el9_8 | ALSA-2026:79281 |
| AlmaLinux 8 | nscd +211 | 2.28-251.el8_10.48 | ALSA-2026:80798 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | glibc | 2.39-142.el10_2 | RLSA-2026:76781 |
| Rocky Linux 9 | glibc | 2.34-283.el9_8 | RLSA-2026:79281 |
| Rocky Linux 8 | glibc | 2.28-251.el8_10.48 | RLSA-2026:80798 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | glibc | 2.38-150600.14.58.1 | SUSE-SU-2026:4250-1 |
| SLES 15 SP6 | glibc | 2.38-150600.14.58.1 | SUSE-SU-2026:4250-1 |
| SLES 15 SP5 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLES 15 SP4 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLES 12 SP5 | glibc | 2.22-114.52.2 | SUSE-SU-2026:4204-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | glibc | 2.40-160000.7.1 | SUSE-SU-2026:23934-1 |
| SLES for SAP 15 SP6 | glibc | 2.38-150600.14.58.1 | SUSE-SU-2026:4250-1 |
| SLES for SAP 15 SP5 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLES for SAP 15 SP4 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLES 16.0 | glibc | 2.40-160000.7.1 | SUSE-SU-2026:23934-1 |
| SLE Micro 6.2 | glibc | 2.40-160000.7.1 | SUSE-SU-2026:23957-1, SUSE-SU-2026:23929-1 |
| SLE Micro 6.1 | glibc | 2.38-slfo.1.1_10.1 | SUSE-SU-2026:23738-1 |
| SLE Micro 6.0 | glibc | 2.38-15.1 | SUSE-SU-2026:23830-1 |
| SLE Micro 5.5 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLE Micro 5.4 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLE Micro 5.3 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLE HPC 15 SP5 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
| SLE HPC 15 SP4 | glibc | 2.31-150300.109.1 | SUSE-SU-2026:4591-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | glibc | 2.44-2.1 | openSUSE-SU-2026:11787-1 |
| openSUSE Leap 16.0 | glibc +4 | 2.40-160000.7.1 | openSUSE-SU-2026:21968-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | glibc | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | glibc +220 | 2.39-145.0.1.el10_2 | ELSA-2026-76781 |
| Oracle Linux 9 | nscd +214 | 2.34-283.0.1.el9_8 | ELSA-2026-79281 |
| Oracle Linux 8 | nscd +213 | 2.28-251.0.5.el8_10.48 | ELSA-2026-80798 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | sln-2.43 +26 | No fix yet | — |
| Wolfi rolling | sln-2.44 +26 | 2.44-r1 | — |
Advisories 26
- WID-SEC-2026-3014 GNU libc: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 9, 2026
- ELSA-2026-76781 Moderate: glibc security, bug fix, and enhancement update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Nov 3, 2026
- ELSA-2026-80798 Moderate: glibc security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 3, 2026
- ELSA-2026-79281 Moderate: glibc security, bug fix, and enhancement update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 2, 2026
- ALSA-2026:79281 Moderate: glibc security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:76781 Moderate: glibc security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:80798 Moderate: glibc security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:80798 Red Hat Security Advisory: glibc security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:79281 Red Hat Security Advisory: glibc security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:76781 Red Hat Security Advisory: glibc security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:59721 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RLSA-2026:80798 Moderate: glibc security update Rocky Linux Security Advisories · Oct 14, 2026
- RLSA-2026:76781 Moderate: glibc security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 11, 2026
- RLSA-2026:79281 Moderate: glibc security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 10, 2026
- SUSE-SU-2026:4591-1 Security update for glibc SUSE / openSUSE Security Updates · Oct 9, 2026
- SUSE-SU-2026:23957-1 Security update for glibc SUSE / openSUSE Security Updates · Oct 2, 2026
- SUSE-SU-2026:23929-1 Security update for glibc SUSE / openSUSE Security Updates · Oct 2, 2026
- SUSE-SU-2026:23934-1 Security update for glibc SUSE / openSUSE Security Updates · Oct 2, 2026
- openSUSE-SU-2026:21968-1 Security update for glibc SUSE / openSUSE Security Updates · Oct 1, 2026
- SUSE-SU-2026:23830-1 Security update for glibc SUSE / openSUSE Security Updates · Sep 27, 2026
- SUSE-SU-2026:23738-1 Security update for glibc SUSE / openSUSE Security Updates · Sep 27, 2026
- SUSE-SU-2026:4250-1 Security update for glibc SUSE / openSUSE Security Updates · Sep 18, 2026
- USN-8737-1 glibc vulnerabilities Ubuntu Security Notices (USN) · Sep 17, 2026
- USN-8737-2 glibc vulnerabilities Ubuntu Security Notices (USN) · Sep 17, 2026
- SUSE-SU-2026:4204-1 Security update for glibc SUSE / openSUSE Security Updates · Sep 16, 2026
- openSUSE-SU-2026:11787-1 glibc-2.44-2.1 on GA media SUSE / openSUSE Security Updates · Sep 16, 2026