RHSA-2026:50807

Vulnerability from csaf_redhat - Published: 2026-08-05 12:24 - Updated: 2026-11-07 05:53
Summary
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
Severity
Moderate
Notes
Topic: An update for Red Hat Hardened Images RPMs is now available.
Details: This update includes the following RPMs: tar: * tar-1.35-9.2.hum1 (aarch64, x86_64) * tar-1.35-9.2.hum1.src (src)
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-2026-18508

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

4.4 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CWE-59 - Improper Link Resolution Before File Access
Affected products
Product Identifier Version Remediation
Unresolved product id: Red Hat Hardened Images:tar-2:1.35-9.2.hum1@aarch64 —
Vendor Fix fix
Workaround
Unresolved product id: Red Hat Hardened Images:tar-2:1.35-9.2.hum1@src —
Vendor Fix fix
Workaround
Unresolved product id: Red Hat Hardened Images:tar-2:1.35-9.2.hum1@x86_64 —
Vendor Fix fix
Workaround
Threats
Impact Moderate
References
Acknowledgments
Red Hat Pavel Cahyna
To clipboard 

{
  "document": {
    "aggregate_severity": {
      "namespace": "https://access.redhat.com/security/updates/classification/",
      "text": "Moderate"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Copyright \u00a9 Red Hat, Inc. All rights reserved.",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "summary",
        "text": "An update for Red Hat Hardened Images RPMs is now available.",
        "title": "Topic"
      },
      {
        "category": "general",
        "text": "This update includes the following RPMs:\n\ntar:\n  * tar-1.35-9.2.hum1 (aarch64, x86_64)\n  * tar-1.35-9.2.hum1.src (src)",
        "title": "Details"
      },
      {
        "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 Red Hat Inc. and provide a link to the original.",
        "title": "Terms of Use"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://access.redhat.com/security/team/contact/",
      "issuing_authority": "Red Hat Product Security is responsible for vulnerability handling across all Red Hat products and services.",
      "name": "Red Hat Product Security",
      "namespace": "https://www.redhat.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "https://access.redhat.com/errata/RHSA-2026:50807",
        "url": "https://access.redhat.com/errata/RHSA-2026:50807"
      },
      {
        "category": "external",
        "summary": "https://images.redhat.com/",
        "url": "https://images.redhat.com/"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/cve/CVE-2026-18508",
        "url": "https://access.redhat.com/security/cve/CVE-2026-18508"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/updates/classification/",
        "url": "https://access.redhat.com/security/updates/classification/"
      },
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_50807.json"
      }
    ],
    "title": "Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update",
    "tracking": {
      "current_release_date": "2026-11-07T05:53:22+00:00",
      "generator": {
        "date": "2026-11-07T05:53:22+00:00",
        "engine": {
          "name": "Red Hat SDEngine",
          "version": "5.4.5"
        }
      },
      "id": "RHSA-2026:50807",
      "initial_release_date": "2026-08-05T12:24:25+00:00",
      "revision_history": [
        {
          "date": "2026-08-05T12:24:25+00:00",
          "number": "1",
          "summary": "Initial version"
        },
        {
          "date": "2026-10-07T14:22:45+00:00",
          "number": "2",
          "summary": "Last updated version"
        },
        {
          "date": "2026-11-07T05:53:22+00:00",
          "number": "3",
          "summary": "Last generated version"
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Red Hat Hardened Images",
                "product": {
                  "name": "Red Hat Hardened Images",
                  "product_id": "Red Hat Hardened Images",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:redhat:hummingbird:1"
                  }
                }
              }
            ],
            "category": "product_family",
            "name": "Red Hat Hardened Images"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "tar-2:1.35-9.2.hum1@aarch64",
                "product": {
                  "name": "tar-2:1.35-9.2.hum1@aarch64",
                  "product_id": "tar-2:1.35-9.2.hum1@aarch64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/tar@1.35-9.2.hum1?arch=aarch64\u0026epoch=2\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-aarch64-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "aarch64"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "tar-2:1.35-9.2.hum1@src",
                "product": {
                  "name": "tar-2:1.35-9.2.hum1@src",
                  "product_id": "tar-2:1.35-9.2.hum1@src",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/tar@1.35-9.2.hum1?arch=src\u0026epoch=2\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-source-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "src"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "tar-2:1.35-9.2.hum1@x86_64",
                "product": {
                  "name": "tar-2:1.35-9.2.hum1@x86_64",
                  "product_id": "tar-2:1.35-9.2.hum1@x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/tar@1.35-9.2.hum1?arch=x86_64\u0026epoch=2\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-x86_64-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          }
        ],
        "category": "vendor",
        "name": "Red Hat"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "tar-2:1.35-9.2.hum1@aarch64 as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@aarch64"
        },
        "product_reference": "tar-2:1.35-9.2.hum1@aarch64",
        "relates_to_product_reference": "Red Hat Hardened Images"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "tar-2:1.35-9.2.hum1@src as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@src"
        },
        "product_reference": "tar-2:1.35-9.2.hum1@src",
        "relates_to_product_reference": "Red Hat Hardened Images"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "tar-2:1.35-9.2.hum1@x86_64 as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@x86_64"
        },
        "product_reference": "tar-2:1.35-9.2.hum1@x86_64",
        "relates_to_product_reference": "Red Hat Hardened Images"
      }
    ]
  },
  "vulnerabilities": [
    {
      "acknowledgments": [
        {
          "names": [
            "Pavel Cahyna"
          ],
          "organization": "Red Hat",
          "summary": "This issue was discovered by Red Hat."
        }
      ],
      "cve": "CVE-2026-18508",
      "cwe": {
        "id": "CWE-59",
        "name": "Improper Link Resolution Before File Access"
      },
      "discovery_date": "2026-07-31T16:57:51.102000+00:00",
      "ids": [
        {
          "system_name": "Red Hat Bugzilla ID",
          "text": "2509843"
        }
      ],
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.",
          "title": "Vulnerability description"
        },
        {
          "category": "summary",
          "text": "tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "Red Hat Enterprise Linux is affected. This issue only applies when the --one-top-level option is used to extract an untrusted archive. Default tar extraction without --one-top-level is not impacted by this specific boundary failure. Users should avoid using --one-top-level as the sole confinement mechanism for untrusted archives until fixed packages are available.",
          "title": "Statement"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product\u0027s status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
        "fixed": [
          "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@aarch64",
          "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@src",
          "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://access.redhat.com/security/cve/CVE-2026-18508"
        },
        {
          "category": "external",
          "summary": "RHBZ#2509843",
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2509843"
        },
        {
          "category": "external",
          "summary": "https://www.cve.org/CVERecord?id=CVE-2026-18508",
          "url": "https://www.cve.org/CVERecord?id=CVE-2026-18508"
        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-18508",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18508"
        }
      ],
      "release_date": "2026-07-31T00:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-08-05T12:24:25+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:tar-2:1.35-9.2.hum1@aarch64",
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@src",
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@x86_64"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:50807"
        },
        {
          "category": "workaround",
          "details": "Do not use --one-top-level as the sole confinement mechanism when extracting untrusted archives. Prefer extracting as an unprivileged user into a freshly created empty directory after changing into that directory (mkdir and cd), avoid extracting as root from sensitive working directories such as /, and follow the GNU tar security guidance for untrusted archives.",
          "product_ids": [
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@aarch64",
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@src",
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 4.4,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@aarch64",
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@src",
            "Red Hat Hardened Images:tar-2:1.35-9.2.hum1@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ],
      "title": "tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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

Author Source Type Date Other

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.