Description
GNU gzip contains a global buffer overflow vulnerability in the LZH decompression logic caused by improper reuse of shared global state between different decompression formats within a single execution. GNU gzip maintains a global array that is shared across the LZ77, LZW, and LZH decompression routines and is not reinitialized between files processed in the same invocation.
By decompressing a specially crafted LZW file followed by a specially crafted LZH file in a single gzip -d command, an attacker can poison the shared global state and subsequently trigger an out‑of‑bounds read in the LZH decoder. The LZH decompression logic follows stale values left in the shared array, causing reads past the end of the allocated global buffer.
This issue has been fixed in commits 63dbf6b3b9e6e781df1a6a64e609b10e23969681 and e7378c2d421be6a286922374425680bbe9ad8b7d.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| GNU | gzip | ≤ 1.14 | — |
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 | gzip | 1.14-1 | — |
| Debian 13 | gzip | 1.13-1+deb13u1 | — |
| Debian 12 | gzip | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | gzip | 1.14-1~exp2ubuntu1.1 | USN-8512-1 |
| Ubuntu 25.10 | gzip | No fix yet | — |
| Ubuntu 24.04 LTS | gzip | 1.12-1ubuntu3.2 | USN-8512-1 |
| Ubuntu 22.04 LTS | gzip | 1.10-4ubuntu4.2 | USN-8512-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | gzip | 1.10-0ubuntu4.1+esm1 | USN-8733-2 |
| Ubuntu Pro 18.04 LTS | gzip | 1.6-5ubuntu1.2+esm1 | USN-8733-2 |
| Ubuntu Pro 16.04 LTS | gzip | 1.6-4ubuntu1+esm2 | USN-8733-1 |
| Ubuntu Pro 14.04 LTS | gzip | 1.6-3ubuntu1+esm2 | USN-8733-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | gzip | 1.13-4.el10_2 | RHSA-2026:61625 |
| RHEL 9 | gzip | 1.12-2.el9_8 | RHSA-2026:61623 |
| RHEL 8 | gzip | 1.9-15.el8_10 | RHSA-2026:65998 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | gzip | 1.14-2.3.hum1 | RHSA-2026:79717, RHSA-2026:37764 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | gzip | 1.13-4.el10_2 | ALSA-2026:61625 |
| AlmaLinux 9 | gzip | 1.12-2.el9_8 | ALSA-2026:61623 |
| AlmaLinux 8 | gzip | 1.9-15.el8_10 | ALSA-2026:65998 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | gzip | 1.13-4.el10_2 | RLSA-2026:61625 |
| Rocky Linux 9 | gzip | 1.12-2.el9_8 | RLSA-2026:61623 |
| Rocky Linux 8 | gzip | 1.9-15.el8_10 | RLSA-2026:65998 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | gzip | 1.10-150200.16.1 | SUSE-SU-2026:3592-1 |
| SLES 12 SP5 | gzip | 1.10-4.20.1 | SUSE-SU-2026:3590-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | gzip | 1.13-160000.4.1 | SUSE-SU-2026:23550-1 |
| SLES 16.0 | gzip | 1.13-160000.4.1 | SUSE-SU-2026:23550-1 |
| SLE Micro 6.2 | gzip | 1.13-160000.4.1 | SUSE-SU-2026:23392-1 |
| SLE Micro 6.1 | gzip | 1.13-slfo.1.1_4.1 | SUSE-SU-2026:23356-1 |
| SLE Micro 6.0 | gzip | 1.13-3.1 | SUSE-SU-2026:23363-1 |
| SLE Micro 5.5 | gzip | 1.10-150200.16.1 | SUSE-SU-2026:3592-1 |
| SLE Micro 5.4 | gzip | 1.10-150200.16.1 | SUSE-SU-2026:3592-1 |
| SLE Micro 5.3 | gzip | 1.10-150200.16.1 | SUSE-SU-2026:3592-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | gzip | 1.14-3.1 | openSUSE-SU-2026:11518-1 |
| openSUSE Leap 16.0 | gzip | 1.13-160000.4.1 | openSUSE-SU-2026:21666-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | gzip | 1.14-r3 | — |
| Alpine v3.23 | gzip | 1.14-r3 | — |
| Alpine v3.22 | gzip | 1.14-r2 | — |
| Alpine v3.21 | gzip | 1.13-r1 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | gzip | 1.13-2 | — |
Advisories 24
- ALSA-2026:61623 Moderate: gzip security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:61625 Moderate: gzip security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:65998 Moderate: gzip security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-2126 gzip: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 13, 2026
- RHSA-2026:79717 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:65998 Red Hat Security Advisory: gzip security update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:61625 Red Hat Security Advisory: gzip security update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:61623 Red Hat Security Advisory: gzip security update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:37764 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- SUSE-SU-2026:23550-1 Security update for gzip SUSE / openSUSE Security Updates · Sep 29, 2026
- USN-8733-2 gzip vulnerabilities Ubuntu Security Notices (USN) · Sep 23, 2026
- SUSE-SU-2026:23392-1 Security update for gzip SUSE / openSUSE Security Updates · Sep 10, 2026
- SUSE-SU-2026:23363-1 Security update for gzip SUSE / openSUSE Security Updates · Sep 10, 2026
- SUSE-SU-2026:23356-1 Security update for gzip SUSE / openSUSE Security Updates · Sep 10, 2026
- VDE-2026-088 METTLER TOLEDO: LabX Standard and Enterprise Report on External Component Analysis - v21.4 CERT@VDE · Sep 10, 2026
- RLSA-2026:65998 Moderate: gzip security update Rocky Linux Security Advisories · Sep 10, 2026
- USN-8733-1 gzip vulnerabilities Ubuntu Security Notices (USN) · Sep 8, 2026
- RLSA-2026:61625 Moderate: gzip security update Rocky Linux Security Advisories · Sep 1, 2026
- RLSA-2026:61623 Moderate: gzip security update Rocky Linux Security Advisories · Sep 1, 2026
- openSUSE-SU-2026:21666-1 Security update for gzip SUSE / openSUSE Security Updates · Aug 28, 2026
- openSUSE-SU-2026:11518-1 gzip-1.14-3.1 on GA media SUSE / openSUSE Security Updates · Aug 16, 2026
- SUSE-SU-2026:3590-1 Security update for gzip SUSE / openSUSE Security Updates · Aug 13, 2026
- SUSE-SU-2026:3592-1 Security update for gzip SUSE / openSUSE Security Updates · Aug 13, 2026
- USN-8512-1 gzip vulnerabilities Ubuntu Security Notices (USN) · Jul 6, 2026
References
- https://cert.pl/en/posts/2026/04/CVE-2026-41991/ third-party-advisory
- https://www.gnu.org/software/gzip/ product
- https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=63dbf6b3b9e6e781df1a6a64e609b10e23969681 patch
- https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=e7378c2d421be6a286922374425680bbe9ad8b7d patch