tar-rs incorrectly ignores PAX size headers if header size is nonzero

{
  "id": "b004be7da8105199bb8b864b9f52f1ebf67f86441e1eb1b60065059b4cc48d4c",
  "url": "https://osv.dev/vulnerability/CVE-2026-33055",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "tar-rs incorrectly ignores PAX size headers if header size is nonzero",
    "summary": "tar-rs is a tar archive reading/writing library for Rust. Versions 0.4.44 and below have conditional logic that skips the PAX size header in cases where the base header size is nonzero. As part of CVE-2025-62518, the astral-tokio-tar project was changed to correctly honor PAX size headers in the case where it was different from the base header. This is almost the inverse of the astral-tokio-tar issue. Any discrepancy in how tar parsers honor file size can be used to create archives that appear differently when unpacked by different archivers. In this case, the tar-rs (Rust tar) crate is an outlier in checking for the header size - other tar parsers (including e.g. Go archive/tar) unconditionally use the PAX size override. This can affect anything that uses the tar crate to parse archives and expects to have a consistent view with other parsers. This issue has been fixed in version 0.4.45.",
    "evidence": "osv:CVE-2026-33055",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-33055",
      "aliases": [
        "CVE-2026-33055",
        "GHSA-gchp-q4r4-x4ff",
        "RUSTSEC-2026-0068"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/composefs/tar-rs",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "096e3d16d14fefac51bc4d94d616b21546ea8bcc"
                },
                {
                  "fixed": "de1a5870e603758f430073688691165f21a33946"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:alexcrichton:tar-rs:*:*:*:*:*:rust:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.4.45"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "de1a5870e603758f430073688691165f21a33946"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.4.44",
            "0.4.43",
            "0.4.42",
            "0.4.41",
            "0.4.40",
            "0.4.39",
            "0.4.38",
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            "0.4.27",
            "0.4.26",
            "0.4.25",
            "0.4.24",
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            "0.4.22",
            "0.4.21",
            "0.4.20",
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            "0.4.18",
            "0.4.17",
            "0.4.16",
            "0.4.15",
            "0.4.14",
            "0.4.13",
            "0.4.12",
            "0.4.11",
            "0.4.10",
            "0.4.9",
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            "0.4.5",
            "0.4.4",
            "0.4.3",
            "0.3.3",
            "0.4.2",
            "0.4.1",
            "v0.4.0",
            "0.4.0",
            "0.3.2",
            "0.3.1",
            "0.3.0",
            "0.2.14",
            "0.2.13",
            "0.2.12",
            "0.2.11",
            "0.2.10",
            "0.2.9",
            "0.2.8",
            "0.2.7",
            "0.2.6",
            "0.2.5",
            "0.2.4",
            "0.2.2",
            "0.2.1",
            "0.1.11",
            "0.1.9",
            "0.1.8",
            "0.1.6",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33055.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:53.433612107Z",
      "provider": "osv",
      "references": [
        "https://www.cve.org/CVERecord?id=CVE-2025-62518",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33055.json",
        "https://github.com/alexcrichton/tar-rs/security/advisories/GHSA-gchp-q4r4-x4ff",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-33055",
        "https://github.com/alexcrichton/tar-rs/commit/de1a5870e603758f430073688691165f21a33946"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-843"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33055.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-33055",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 522079,
  "published_at": "2026-03-20T07:06:08.39+00:00"
}