{"id":"CVE-2026-9546","state":"PUBLISHED","title":"sending old referer","description":"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.","publishedAt":"2026-07-03T06:18:14.447Z","updatedAt":"2026-09-15T06:03:33.325Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","source":"CISA-ADP"},"assigner":"curl","products":["curl curl"],"affected":[{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.18.0","status":"affected","lessThan":"8.20.1","versionType":"semver"}]},{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"2cb868242dc2ac9cd52ee64987ef51d5964a56f9","status":"affected","lessThan":"862e8a74a84478d82973471b4f49dc2746c1780e","versionType":"git"}],"repo":"https://github.com/curl/curl.git"},{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.20.0","status":"affected"},{"version":"8.19.0","status":"affected"},{"version":"8.18.0","status":"affected"}]}],"references":["https://curl.se/docs/CVE-2026-9546.json","https://curl.se/docs/CVE-2026-9546.html","https://hackerone.com/reports/3754343"],"weaknesses":["CWE-200"],"ingestedAt":"2026-10-29T20:13:52.441Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/9xxx/CVE-2026-9546.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-9546","state":"PUBLISHED","datePublished":"2026-07-03T06:18:14.447Z","dateUpdated":"2026-09-15T06:03:33.325Z","assignerShortName":"curl","assignerOrgId":"2499f714-1537-4658-8207-48ae4bb9eae9","dateReserved":"2026-05-26T06:45:18.723Z"},"containers":{"cna":{"title":"sending old referer","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.18.0","status":"affected","lessThan":"8.20.1","versionType":"semver"}]},{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"2cb868242dc2ac9cd52ee64987ef51d5964a56f9","status":"affected","lessThan":"862e8a74a84478d82973471b4f49dc2746c1780e","versionType":"git"}],"repo":"https://github.com/curl/curl.git"},{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.20.0","status":"affected"},{"version":"8.19.0","status":"affected"},{"version":"8.18.0","status":"affected"}]}],"references":[{"url":"https://curl.se/docs/CVE-2026-9546.json"},{"url":"https://curl.se/docs/CVE-2026-9546.html"},{"url":"https://hackerone.com/reports/3754343"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-200","lang":"en","description":"Exposure of Sensitive Information to an Unauthorized Actor","type":"CWE"}]}],"providerMetadata":{"shortName":"curl","orgId":"2499f714-1537-4658-8207-48ae4bb9eae9","dateUpdated":"2026-09-15T06:03:33.325Z"},"x_osv":{"schema_version":"1.5.0","id":"CURL-CVE-2026-9546","aliases":["CVE-2026-9546"],"summary":"sending old referer","modified":"2026-09-07T10:34:51.00Z","database_specific":{"package":"curl","affects":"lib","URL":"https://curl.se/docs/CVE-2026-9546.json","www":"https://curl.se/docs/CVE-2026-9546.html","issue":"https://hackerone.com/reports/3754343","CWE":{"id":"CWE-200","desc":"Exposure of Sensitive Information to an Unauthorized Actor"},"last_affected":"8.20.0","severity":"Low"},"published":"2026-06-24T08:00:00.00Z","affected":[{"ranges":[{"type":"SEMVER","events":[{"introduced":"8.18.0"},{"fixed":"8.20.1"}]},{"type":"GIT","repo":"https://github.com/curl/curl.git","events":[{"introduced":"2cb868242dc2ac9cd52ee64987ef51d5964a56f9"},{"fixed":"862e8a74a84478d82973471b4f49dc2746c1780e"}]}],"versions":["8.20.0","8.19.0","8.18.0"]}],"credits":[{"name":"renjian on hackerone","type":"finder"},{"name":"Daniel Stenberg","type":"remediation developer"}],"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."},"credits":[{"lang":"en","value":"renjian on hackerone","type":"finder"},{"lang":"en","value":"Daniel Stenberg","type":"remediation developer"}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://hackerone.com/reports/3754343","tags":["exploit"]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.5,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-07-06T16:51:06.094113Z","id":"CVE-2026-9546","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-06T16:51:49.410Z"}}]}}}