{"id":"CVE-2026-9546","summary":"sending old referer","details":"A vulnerability in libcurl caused the HTTP `Referer:` header to persist even\nwhen explicitly cleared. While the documentation states that passing NULL to\n`CURLOPT_REFERER` suppresses the header, the option failed to clear the\ninternal state. As a result, the previous referrer string was erroneously\nreused and sent in subsequent requests, potentially leaking sensitive\ninformation to unintended servers.","aliases":["CURL-CVE-2026-9546"],"modified":"2026-11-03T22:57:09.491346818Z","published":"2026-07-03T06:18:14.447Z","related":["SUSE-SU-2026:5068-1","SUSE-SU-2026:5069-1","openSUSE-SU-2026:11230-1"],"database_specific":{"cna_assigner":"curl","cwe_ids":["CWE-200"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9546.json"},"references":[{"type":"WEB","url":"https://curl.se/docs/CVE-2026-9546.html"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-9546.json"},{"type":"WEB","url":"https://hackerone.com/reports/3754343"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9546.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9546"},{"type":"PACKAGE","url":"https://github.com/curl/curl.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/curl/curl","events":[{"introduced":"2eebc58c4b8d68c98c8344381a9f6df4cca838fd"},{"fixed":"68720b4837284335b2d63cb358f8f6ce65f5bc55"}],"database_specific":{"extracted_events":[{"cpe":"cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*","range":[{"introduced":"8.18.0"},{"fixed":"8.21.0"}],"source":"CPE_RANGE"}]}},{"type":"GIT","repo":"https://github.com/curl/curl.git","events":[{"introduced":"2cb868242dc2ac9cd52ee64987ef51d5964a56f9"},{"fixed":"862e8a74a84478d82973471b4f49dc2746c1780e"}],"database_specific":{"extracted_events":[{"strategy":"StandardRange","range":[{"introduced":"2cb868242dc2ac9cd52ee64987ef51d5964a56f9"},{"fixed":"862e8a74a84478d82973471b4f49dc2746c1780e"}],"source":"AFFECTED_FIELD"}]}}],"versions":["8.18.0","8.19.0","8.20.0","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","curl-8_18_0","rc-8_19_0-3","rc-8_19_0-2","rc-8_19_0-1","rc-8_18_0-3","rc-8_18_0-2","rc-8_18_0-1"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-9546.json","vanir_signatures":[{"signature_version":"v1","source":"https://github.com/curl/curl.git/commit/862e8a74a84478d82973471b4f49dc2746c1780e","target":{"file":"lib/transfer.c"},"deprecated":false,"digest":{"threshold":0.9,"line_hashes":["329802710635362475633966257142929289229","59722172210655117825890418870938329781","183831522990858182837473479172905867047","304554302798540308152858876043779062238"]},"id":"CVE-2026-9546-7ba9ca43","signature_type":"Line"},{"signature_type":"Function","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/862e8a74a84478d82973471b4f49dc2746c1780e","target":{"file":"lib/transfer.c","function":"Curl_pretransfer"},"deprecated":false,"digest":{"function_hash":"192731219037552860576466850254657292841","length":3790},"id":"CVE-2026-9546-93bc1aa3"}],"vanir_signatures_modified":"2026-10-24T14:22:08Z"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}