CVE-2026-41991
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Description
A flaw was found in the gzexe utility of GNU gzip. When the mktemp utility is not available, gzexe creates temporary files with predictable names based on the process ID. A local attacker can exploit this by pre-creating a symbolic link to an arbitrary file at the predicted temporary file path. This can lead to a Time-of-Check to Time-of-Use (TOCTOU) condition, allowing the attacker to overwrite arbitrary files on the system.
Statement
A flaw was found in the gzexe utility of GNU gzip. When the mktemp utility is not available in the user's PATH, gzexe creates temporary files with predictable names based on the process ID. A local attacker can exploit this by creating a symbolic link at the predicted temporary file path, leading to a TOCTOU race condition that allows arbitrary file overwrite. On Red Hat Enterprise Linux, mktemp is provided by coreutils which is always installed, making the vulnerable fallback code path effectively unreachable in standard deployments.
Mitigation
Ensure that the mktemp utility (provided by the coreutils package) is available in PATH when using the gzexe utility. On Red Hat Enterprise Linux, mktemp is installed by default and no additional action is needed.
Additional information
- This content is not included.Bugzilla 2494158: gzip: gzip: Arbitrary file overwrite via insecure temporary file handling in gzexe utility
- Content from cwe.mitre.org is not included.CWE-59: Improper Link Resolution Before File Access ('Link Following')
External References
Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2026-41991
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2026-41991
Content from cert.pl is not included.https://cert.pl/en/posts/2026/04/CVE-2026-41991/
Content from www.gnu.org is not included.https://www.gnu.org/software/gzip/
Affected Packages and Issued Red Hat Security Errata
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.
| Products / Services | Components | State | Errata |
|---|---|---|---|
| Red Hat Discovery 2 | discovery/discovery-server-rhel9 | Fixed | RHSA-2026:61783 |
| Red Hat Enterprise Linux 10 | gzip | Fixed | RHSA-2026:61625 |
| Red Hat Enterprise Linux 6 | gzip | Fix deferred | |
| Red Hat Enterprise Linux 7 | gzip | Fix deferred | |
| Red Hat Enterprise Linux 8 | gzip | Fix deferred | |
| Red Hat Enterprise Linux 9 | gzip | Fixed | RHSA-2026:61623 |
| Red Hat Hardened Images | gzip-main | Fixed | RHSA-2026:33771 |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Fix deferred | |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Fix deferred | |
| Red Hat OpenShift Dev Spaces | devspaces/code-sshd-rhel9 | Fix deferred | |
| No matching records found | |||
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| CVSS v3 Base Score | 6 | 4.7 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | Required | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | None | N/A |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:H
NVD CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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