{ "document": { "aggregate_severity": { "text": "Medium" }, "category": "csaf_vex", "csaf_version": "2.0", "distribution": { "text": "TuxCare License Agreement", "tlp": { "label": "WHITE", "url": "https://www.first.org/tlp/" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "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 Cloud Linux Inc. and provide a link to the original.", "title": "Terms of Use" } ], "publisher": { "category": "vendor", "contact_details": "https://tuxcare.com/contact/", "name": "TuxCare", "namespace": "https://tuxcare.com/" }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://security.tuxcare.com/csaf/v2/els_os/debian11els/vex/2026/cve-2026-41991-els_os-debian11els.json" } ], "tracking": { "current_release_date": "2026-09-12T12:38:33Z", "generator": { "date": "2026-09-12T12:38:33Z", "engine": { "name": "pyCSAF" } }, "id": "CVE-2026-41991-ELS_OS-DEBIAN11ELS", "initial_release_date": "2026-06-29T12:16:00Z", "revision_history": [ { "date": "2026-06-29T12:16:00Z", "number": "1", "summary": "Initial version" }, { "date": "2026-09-12T12:38:33Z", "number": "2", "summary": "Official Publication" } ], "status": "final", "version": "2" }, "title": "Security update on CVE-2026-41991" }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_name", "name": "Debian 11", "product": { "name": "Debian 11", "product_id": "Debian-11", "product_identification_helper": { "cpe": "cpe:2.3:o:debian:debian_linux:11:*:*:*:*:*:*:*" } } } ], "category": "product_family", "name": "Debian" }, { "branches": [ { "category": "product_version", "name": "gzip-0:1.10-4+deb11u1.armel", "product": { "name": "gzip-0:1.10-4+deb11u1.armel", "product_id": "gzip-0:1.10-4+deb11u1.armel", "product_identification_helper": { "purl": "pkg:deb/debian/gzip@1.10-4%2Bdeb11u1?arch=armel" } } } ], "category": "architecture", "name": "armel" }, { "branches": [ { "category": "product_version", "name": "gzip-0:1.10-4+deb11u1.amd64", "product": { "name": "gzip-0:1.10-4+deb11u1.amd64", "product_id": "gzip-0:1.10-4+deb11u1.amd64", "product_identification_helper": { "purl": "pkg:deb/debian/gzip@1.10-4%2Bdeb11u1?arch=amd64" } } } ], "category": "architecture", "name": "amd64" }, { "branches": [ { "category": "product_version", "name": "gzip-0:1.10-4+deb11u1.arm64", "product": { "name": "gzip-0:1.10-4+deb11u1.arm64", "product_id": "gzip-0:1.10-4+deb11u1.arm64", "product_identification_helper": { "purl": "pkg:deb/debian/gzip@1.10-4%2Bdeb11u1?arch=arm64" } } } ], "category": "architecture", "name": "arm64" }, { "branches": [ { "category": "product_version", "name": "gzip-win32-0:1.10-4+deb11u1.all", "product": { "name": "gzip-win32-0:1.10-4+deb11u1.all", "product_id": "gzip-win32-0:1.10-4+deb11u1.all", "product_identification_helper": { "purl": "pkg:deb/debian/gzip-win32@1.10-4%2Bdeb11u1?arch=all" } } } ], "category": "architecture", "name": "all" } ], "category": "vendor", "name": "Software in the Public Interest, Inc." }, { "branches": [ { "branches": [ { "category": "product_version", "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.armel", "product": { "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.armel", "product_id": "gzip-0:1.10-4+deb11u1+tuxcare.els1.armel", "product_identification_helper": { "purl": "pkg:deb/tuxcare/gzip@1.10-4%2Bdeb11u1%2Btuxcare.els1?arch=armel" } } } ], "category": "architecture", "name": "armel" }, { "branches": [ { "category": "product_version", "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64", "product": { "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64", "product_id": "gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64", "product_identification_helper": { "purl": "pkg:deb/tuxcare/gzip@1.10-4%2Bdeb11u1%2Btuxcare.els1?arch=amd64" } } } ], "category": "architecture", "name": "amd64" }, { "branches": [ { "category": "product_version", "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64", "product": { "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64", "product_id": "gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64", "product_identification_helper": { "purl": "pkg:deb/tuxcare/gzip@1.10-4%2Bdeb11u1%2Btuxcare.els1?arch=arm64" } } } ], "category": "architecture", "name": "arm64" }, { "branches": [ { "category": "product_version", "name": "gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all", "product": { "name": "gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all", "product_id": "gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all", "product_identification_helper": { "purl": "pkg:deb/tuxcare/gzip-win32@1.10-4%2Bdeb11u1%2Btuxcare.els1?arch=all" } } } ], "category": "architecture", "name": "all" } ], "category": "vendor", "name": "TuxCare" } ], "relationships": [ { "category": "default_component_of", "full_product_name": { "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.armel as a component of Debian 11", "product_id": "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.armel" }, "product_reference": "gzip-0:1.10-4+deb11u1+tuxcare.els1.armel", "relates_to_product_reference": "Debian-11" }, { "category": "default_component_of", "full_product_name": { "name": "gzip-0:1.10-4+deb11u1.armel as a component of Debian 11", "product_id": "Debian-11:gzip-0:1.10-4+deb11u1.armel" }, "product_reference": "gzip-0:1.10-4+deb11u1.armel", "relates_to_product_reference": "Debian-11" }, { "category": "default_component_of", "full_product_name": { "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64 as a component of Debian 11", "product_id": "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64" }, "product_reference": "gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64", "relates_to_product_reference": "Debian-11" }, { "category": "default_component_of", "full_product_name": { "name": "gzip-0:1.10-4+deb11u1.amd64 as a component of Debian 11", "product_id": "Debian-11:gzip-0:1.10-4+deb11u1.amd64" }, "product_reference": "gzip-0:1.10-4+deb11u1.amd64", "relates_to_product_reference": "Debian-11" }, { "category": "default_component_of", "full_product_name": { "name": "gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64 as a component of Debian 11", "product_id": "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64" }, "product_reference": "gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64", "relates_to_product_reference": "Debian-11" }, { "category": "default_component_of", "full_product_name": { "name": "gzip-0:1.10-4+deb11u1.arm64 as a component of Debian 11", "product_id": "Debian-11:gzip-0:1.10-4+deb11u1.arm64" }, "product_reference": "gzip-0:1.10-4+deb11u1.arm64", "relates_to_product_reference": "Debian-11" }, { "category": "default_component_of", "full_product_name": { "name": "gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all as a component of Debian 11", "product_id": "Debian-11:gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all" }, "product_reference": "gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all", "relates_to_product_reference": "Debian-11" }, { "category": "default_component_of", "full_product_name": { "name": "gzip-win32-0:1.10-4+deb11u1.all as a component of Debian 11", "product_id": "Debian-11:gzip-win32-0:1.10-4+deb11u1.all" }, "product_reference": "gzip-win32-0:1.10-4+deb11u1.all", "relates_to_product_reference": "Debian-11" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-41991", "cwe": { "id": "CWE-377", "name": "Insecure Temporary File" }, "notes": [ { "category": "description", "text": "GNU gzip contains a vulnerability in the gzexe utility related to insecure temporary file handling. When the mktemp utility is not available in the user’s PATH, gzexe falls back to constructing a temporary file path based solely on the process ID (PID). This predictable filename is created without exclusive access or existence checks.\nA local attacker can pre‑create the predicted temporary file path as a symbolic link pointing to an arbitrary file writable by the victim. When gzexe runs, it follows the symlink and overwrites the target file, resulting in a time‑of‑check to time‑of‑use (TOCTOU) condition that allows arbitrary file overwrite.\n\nThis issue has been fixed in the commit 4e6f8b24ab823146ab8776f0b7fe486ab34d4269", "title": "Vulnerability description" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "known_affected": [ "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64", "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64", "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.armel", "Debian-11:gzip-0:1.10-4+deb11u1.amd64", "Debian-11:gzip-0:1.10-4+deb11u1.arm64", "Debian-11:gzip-0:1.10-4+deb11u1.armel", "Debian-11:gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all", "Debian-11:gzip-win32-0:1.10-4+deb11u1.all" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/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": "2026-06-29T12:16:00Z", "remediations": [ { "category": "no_fix_planned", "date": "2026-09-07T14:43:29.741292Z", "details": "This is a local-only TOCTOU in the gzexe helper that is reachable only when a user explicitly runs gzexe and only if mktemp is missing from PATH; standard Linux installations provide mktemp via coreutils, so the PID-based fallback is not exercised in default configurations. Even if triggered, it does not bypass filesystem permissions and can only overwrite files writable by the invoking user (no privilege escalation, no confidentiality or availability impact). Because gzexe is not invoked by system services or package managers, exploitation requires interactive local use, making this low priority for centrally managed servers and VMs.", "product_ids": [ "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64", "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64", "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.armel", "Debian-11:gzip-0:1.10-4+deb11u1.amd64", "Debian-11:gzip-0:1.10-4+deb11u1.arm64", "Debian-11:gzip-0:1.10-4+deb11u1.armel", "Debian-11:gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all", "Debian-11:gzip-win32-0:1.10-4+deb11u1.all" ] } ], "scores": [ { "cvss_v3": { "attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 4.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N", "version": "3.1" }, "products": [ "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.amd64", "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.arm64", "Debian-11:gzip-0:1.10-4+deb11u1+tuxcare.els1.armel", "Debian-11:gzip-0:1.10-4+deb11u1.amd64", "Debian-11:gzip-0:1.10-4+deb11u1.arm64", "Debian-11:gzip-0:1.10-4+deb11u1.armel", "Debian-11:gzip-win32-0:1.10-4+deb11u1+tuxcare.els1.all", "Debian-11:gzip-win32-0:1.10-4+deb11u1.all" ] } ], "threats": [ { "category": "impact", "details": "Moderate" } ] } ] }