secure cookie attribute bypass with tab

{
  "id": "2b48275f2fb405924f563bb98776073e4d6303d7696dcb352a456a5f8d9f8a5e",
  "url": "https://osv.dev/vulnerability/CURL-CVE-2026-80255",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "secure cookie attribute bypass with tab",
    "summary": "A `Set-Cookie:` header using tab (horizontal tab, ASCII code 9) instead of space (ascii code 32) immediately before the `Secure` attribute causes curl to store the cookie without its Secure flag. The cookie might then wrongfully be sent over plaintext HTTP on subsequent requests to the same host.",
    "evidence": "osv:CURL-CVE-2026-80255",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CURL-CVE-2026-80255",
      "aliases": [
        "CURL-CVE-2026-80255",
        "CVE-2026-80255"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "8.13.0"
                },
                {
                  "fixed": "8.14.2"
                },
                {
                  "introduced": "8.15.0"
                },
                {
                  "fixed": "8.16.1"
                },
                {
                  "introduced": "8.17.0"
                },
                {
                  "fixed": "8.20.1"
                },
                {
                  "introduced": "8.21.0"
                },
                {
                  "fixed": "8.22.0"
                }
              ]
            },
            {
              "repo": "https://github.com/curl/curl.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1aea05a6c2699e80c75936d58569851555acd603"
                },
                {
                  "fixed": "4f6aa41a0145e930e766775dbe860883d350aa0a"
                }
              ]
            }
          ],
          "versions": [
            "8.21.0",
            "8.20.0",
            "8.19.0",
            "8.18.0",
            "8.17.0",
            "8.16.0",
            "8.15.0",
            "8.14.1",
            "8.14.0",
            "8.13.0",
            "rc-8_22_0-3",
            "rc-8_22_0-2",
            "rc-8_22_0-1",
            "curl-8_21_0",
            "rc-8_21_0-3",
            "rc-8_21_0-2",
            "rc-8_21_0-1",
            "curl-8_20_0",
            "rc-8_20_0-3",
            "rc-8_20_0-2",
            "rc-8_20_0-1",
            "curl-8_19_0",
            "rc-8_19_0-3",
            "rc-8_19_0-2",
            "rc-8_19_0-1",
            "curl-8_18_0",
            "rc-8_18_0-3",
            "rc-8_18_0-2",
            "rc-8_18_0-1",
            "curl-8_17_0",
            "curl-8_16_0",
            "curl-8_15_0",
            "curl-8_14_1",
            "curl-8_14_0",
            "curl-8_13_0"
          ],
          "database_specific": {
            "source": "https://curl.se/docs/CURL-CVE-2026-80255.json",
            "vanir_signatures": [
              {
                "id": "CURL-CVE-2026-80255-1976306a",
                "digest": {
                  "length": 1807,
                  "function_hash": "156248508838678620174316832758863728670"
                },
                "source": "https://github.com/curl/curl.git/commit/4f6aa41a0145e930e766775dbe860883d350aa0a",
                "target": {
                  "file": "lib/cookie.c",
                  "function": "parse_cookie_header"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CURL-CVE-2026-80255-d501f15b",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "205816004684899671603710379302867268706",
                    "18514482557387433468133516516178791980",
                    "274291864640093038674042589109486318957",
                    "147342966625047719758808367123869032769"
                  ]
                },
                "source": "https://github.com/curl/curl.git/commit/4f6aa41a0145e930e766775dbe860883d350aa0a",
                "target": {
                  "file": "lib/cookie.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-25T01:05:44Z"
          }
        }
      ],
      "modified": "2026-10-25T01:05:44.226162024Z",
      "provider": "osv",
      "references": [],
      "provider_metadata": {
        "CWE": {
          "id": "CWE-201",
          "desc": "Information Exposure Through Sent Data"
        },
        "URL": "https://curl.se/docs/CVE-2026-80255.json",
        "www": "https://curl.se/docs/CVE-2026-80255.html",
        "issue": "https://hackerone.com/reports/3972395",
        "affects": "both",
        "package": "curl",
        "severity": "Low",
        "last_affected": "8.21.0"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-80255",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 444423,
  "published_at": "2026-09-02T08:00:00+00:00"
}