RHSA-2026:33771

Vulnerability from csaf_redhat - Published: 2026-06-30 20:49 - Updated: 2026-07-01 14:20
Summary
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Severity
Moderate
Notes
Topic: An update for Red Hat Hardened Images RPMs is now available.
Details: This update includes the following RPMs: gzip: * gzip-1.14-2.2.hum1 (aarch64, x86_64) * gzip-1.14-2.2.hum1.src (src) Security Fix(es): gzip: * CVE-2026-41911 * CVE-2026-41991
Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.
CVE-2026-41991

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.

6.0 (Medium)
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:H
CWE-59 - Improper Link Resolution Before File Access ('Link Following')
Affected products
Product Identifier Version Remediation
Unresolved product id: Red Hat Hardened Images:gzip-main@aarch64 —
Vendor Fix fix
Workaround
Unresolved product id: Red Hat Hardened Images:gzip-main@src —
Vendor Fix fix
Workaround
Unresolved product id: Red Hat Hardened Images:gzip-main@x86_64 —
Vendor Fix fix
Workaround
Threats
Impact Moderate
References
To clipboard 

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      },
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        "text": "This update includes the following RPMs:\n\ngzip:\n  * gzip-1.14-2.2.hum1 (aarch64, x86_64)\n  * gzip-1.14-2.2.hum1.src (src)\n\nSecurity Fix(es):\n\ngzip:\n  * CVE-2026-41911\n  * CVE-2026-41991",
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  "vulnerabilities": [
    {
      "cve": "CVE-2026-41991",
      "cwe": {
        "id": "CWE-59",
        "name": "Improper Link Resolution Before File Access (\u0027Link Following\u0027)"
      },
      "discovery_date": "2026-06-29T12:01:03.862009+00:00",
      "ids": [
        {
          "system_name": "Red Hat Bugzilla ID",
          "text": "2494158"
        }
      ],
      "notes": [
        {
          "category": "description",
          "text": "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.",
          "title": "Vulnerability description"
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        {
          "category": "summary",
          "text": "gzip: gzip: Arbitrary file overwrite via insecure temporary file handling in gzexe utility",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "A flaw was found in the gzexe utility of GNU gzip. When the mktemp utility is not available in the user\u0027s 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.",
          "title": "Statement"
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          "title": "CVSS score applicability"
        }
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          "Red Hat Hardened Images:gzip-main@src",
          "Red Hat Hardened Images:gzip-main@x86_64"
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        },
        {
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          "summary": "RHBZ#2494158",
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2494158"
        },
        {
          "category": "external",
          "summary": "https://www.cve.org/CVERecord?id=CVE-2026-41991",
          "url": "https://www.cve.org/CVERecord?id=CVE-2026-41991"
        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-41991",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-41991"
        },
        {
          "category": "external",
          "summary": "https://cert.pl/en/posts/2026/04/CVE-2026-41991/",
          "url": "https://cert.pl/en/posts/2026/04/CVE-2026-41991/"
        },
        {
          "category": "external",
          "summary": "https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269",
          "url": "https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269"
        },
        {
          "category": "external",
          "summary": "https://www.gnu.org/software/gzip/",
          "url": "https://www.gnu.org/software/gzip/"
        }
      ],
      "release_date": "2026-06-29T10:15:50.766000+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-06-30T20:49:50+00:00",
          "details": "For details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/",
          "product_ids": [
            "Red Hat Hardened Images:gzip-main@aarch64",
            "Red Hat Hardened Images:gzip-main@src",
            "Red Hat Hardened Images:gzip-main@x86_64"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:33771"
        },
        {
          "category": "workaround",
          "details": "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.",
          "product_ids": [
            "Red Hat Hardened Images:gzip-main@aarch64",
            "Red Hat Hardened Images:gzip-main@src",
            "Red Hat Hardened Images:gzip-main@x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 6.0,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:gzip-main@aarch64",
            "Red Hat Hardened Images:gzip-main@src",
            "Red Hat Hardened Images:gzip-main@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ],
      "title": "gzip: gzip: Arbitrary file overwrite via insecure temporary file handling in gzexe utility"
    }
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.