{"id":"CVE-2026-86409","state":"PUBLISHED","title":"stale SigV4 headers sent unintended","description":"Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication,\ncontrary to expectations and documentation. A subsequent transfer on the same\nhandle still sends an `Authorization: AWS4-HMAC-SHA256` header to whatever URL\nisset next, leaking state information.","publishedAt":"2026-10-20T19:57:01.794Z","updatedAt":"2026-10-29T18:33:49.983Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"CISA-ADP"},"assigner":"curl","products":["curl curl"],"affected":[{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.21.0","status":"affected","lessThanOrEqual":"8.21.0","versionType":"semver"},{"version":"8.20.0","status":"affected","lessThanOrEqual":"8.20.0","versionType":"semver"},{"version":"8.19.0","status":"affected","lessThanOrEqual":"8.19.0","versionType":"semver"},{"version":"8.18.0","status":"affected","lessThanOrEqual":"8.18.0","versionType":"semver"},{"version":"8.17.0","status":"affected","lessThanOrEqual":"8.17.0","versionType":"semver"},{"version":"8.16.0","status":"affected","lessThanOrEqual":"8.16.0","versionType":"semver"},{"version":"8.15.0","status":"affected","lessThanOrEqual":"8.15.0","versionType":"semver"},{"version":"8.14.1","status":"affected","lessThanOrEqual":"8.14.1","versionType":"semver"},{"version":"8.14.0","status":"affected","lessThanOrEqual":"8.14.0","versionType":"semver"},{"version":"8.13.0","status":"affected","lessThanOrEqual":"8.13.0","versionType":"semver"},{"version":"8.12.1","status":"affected","lessThanOrEqual":"8.12.1","versionType":"semver"},{"version":"8.12.0","status":"affected","lessThanOrEqual":"8.12.0","versionType":"semver"},{"version":"8.11.1","status":"affected","lessThanOrEqual":"8.11.1","versionType":"semver"},{"version":"8.11.0","status":"affected","lessThanOrEqual":"8.11.0","versionType":"semver"},{"version":"8.10.1","status":"affected","lessThanOrEqual":"8.10.1","versionType":"semver"},{"version":"8.10.0","status":"affected","lessThanOrEqual":"8.10.0","versionType":"semver"},{"version":"8.9.1","status":"affected","lessThanOrEqual":"8.9.1","versionType":"semver"},{"version":"8.9.0","status":"affected","lessThanOrEqual":"8.9.0","versionType":"semver"},{"version":"8.8.0","status":"affected","lessThanOrEqual":"8.8.0","versionType":"semver"},{"version":"8.7.1","status":"affected","lessThanOrEqual":"8.7.1","versionType":"semver"},{"version":"8.7.0","status":"affected","lessThanOrEqual":"8.7.0","versionType":"semver"},{"version":"8.6.0","status":"affected","lessThanOrEqual":"8.6.0","versionType":"semver"},{"version":"8.5.0","status":"affected","lessThanOrEqual":"8.5.0","versionType":"semver"},{"version":"8.4.0","status":"affected","lessThanOrEqual":"8.4.0","versionType":"semver"},{"version":"8.3.0","status":"affected","lessThanOrEqual":"8.3.0","versionType":"semver"},{"version":"8.2.1","status":"affected","lessThanOrEqual":"8.2.1","versionType":"semver"},{"version":"8.2.0","status":"affected","lessThanOrEqual":"8.2.0","versionType":"semver"},{"version":"8.1.2","status":"affected","lessThanOrEqual":"8.1.2","versionType":"semver"},{"version":"8.1.1","status":"affected","lessThanOrEqual":"8.1.1","versionType":"semver"},{"version":"8.1.0","status":"affected","lessThanOrEqual":"8.1.0","versionType":"semver"},{"version":"8.0.1","status":"affected","lessThanOrEqual":"8.0.1","versionType":"semver"},{"version":"8.0.0","status":"affected","lessThanOrEqual":"8.0.0","versionType":"semver"},{"version":"7.88.1","status":"affected","lessThanOrEqual":"7.88.1","versionType":"semver"},{"version":"7.88.0","status":"affected","lessThanOrEqual":"7.88.0","versionType":"semver"},{"version":"7.87.0","status":"affected","lessThanOrEqual":"7.87.0","versionType":"semver"},{"version":"7.86.0","status":"affected","lessThanOrEqual":"7.86.0","versionType":"semver"},{"version":"7.85.0","status":"affected","lessThanOrEqual":"7.85.0","versionType":"semver"},{"version":"7.84.0","status":"affected","lessThanOrEqual":"7.84.0","versionType":"semver"},{"version":"7.83.1","status":"affected","lessThanOrEqual":"7.83.1","versionType":"semver"},{"version":"7.83.0","status":"affected","lessThanOrEqual":"7.83.0","versionType":"semver"},{"version":"7.82.0","status":"affected","lessThanOrEqual":"7.82.0","versionType":"semver"},{"version":"7.81.0","status":"affected","lessThanOrEqual":"7.81.0","versionType":"semver"},{"version":"7.80.0","status":"affected","lessThanOrEqual":"7.80.0","versionType":"semver"},{"version":"7.79.1","status":"affected","lessThanOrEqual":"7.79.1","versionType":"semver"},{"version":"7.79.0","status":"affected","lessThanOrEqual":"7.79.0","versionType":"semver"},{"version":"7.78.0","status":"affected","lessThanOrEqual":"7.78.0","versionType":"semver"},{"version":"7.77.0","status":"affected","lessThanOrEqual":"7.77.0","versionType":"semver"},{"version":"7.76.1","status":"affected","lessThanOrEqual":"7.76.1","versionType":"semver"},{"version":"7.76.0","status":"affected","lessThanOrEqual":"7.76.0","versionType":"semver"},{"version":"7.75.0","status":"affected","lessThanOrEqual":"7.75.0","versionType":"semver"}]}],"references":["https://curl.se/docs/CVE-2026-86409.json","https://curl.se/docs/CVE-2026-86409.html","https://hackerone.com/reports/3973135"],"weaknesses":["CWE-201"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/86xxx/CVE-2026-86409.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-86409","state":"PUBLISHED","datePublished":"2026-10-20T19:57:01.794Z","dateUpdated":"2026-10-29T18:33:49.983Z","assignerShortName":"curl","assignerOrgId":"2499f714-1537-4658-8207-48ae4bb9eae9","dateReserved":"2026-09-07T12:11:44.926Z"},"containers":{"cna":{"title":"stale SigV4 headers sent unintended","descriptions":[{"lang":"en","value":"Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication,\ncontrary to expectations and documentation. A subsequent transfer on the same\nhandle still sends an `Authorization: AWS4-HMAC-SHA256` header to whatever URL\nisset next, leaking state information."}],"affected":[{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.21.0","status":"affected","lessThanOrEqual":"8.21.0","versionType":"semver"},{"version":"8.20.0","status":"affected","lessThanOrEqual":"8.20.0","versionType":"semver"},{"version":"8.19.0","status":"affected","lessThanOrEqual":"8.19.0","versionType":"semver"},{"version":"8.18.0","status":"affected","lessThanOrEqual":"8.18.0","versionType":"semver"},{"version":"8.17.0","status":"affected","lessThanOrEqual":"8.17.0","versionType":"semver"},{"version":"8.16.0","status":"affected","lessThanOrEqual":"8.16.0","versionType":"semver"},{"version":"8.15.0","status":"affected","lessThanOrEqual":"8.15.0","versionType":"semver"},{"version":"8.14.1","status":"affected","lessThanOrEqual":"8.14.1","versionType":"semver"},{"version":"8.14.0","status":"affected","lessThanOrEqual":"8.14.0","versionType":"semver"},{"version":"8.13.0","status":"affected","lessThanOrEqual":"8.13.0","versionType":"semver"},{"version":"8.12.1","status":"affected","lessThanOrEqual":"8.12.1","versionType":"semver"},{"version":"8.12.0","status":"affected","lessThanOrEqual":"8.12.0","versionType":"semver"},{"version":"8.11.1","status":"affected","lessThanOrEqual":"8.11.1","versionType":"semver"},{"version":"8.11.0","status":"affected","lessThanOrEqual":"8.11.0","versionType":"semver"},{"version":"8.10.1","status":"affected","lessThanOrEqual":"8.10.1","versionType":"semver"},{"version":"8.10.0","status":"affected","lessThanOrEqual":"8.10.0","versionType":"semver"},{"version":"8.9.1","status":"affected","lessThanOrEqual":"8.9.1","versionType":"semver"},{"version":"8.9.0","status":"affected","lessThanOrEqual":"8.9.0","versionType":"semver"},{"version":"8.8.0","status":"affected","lessThanOrEqual":"8.8.0","versionType":"semver"},{"version":"8.7.1","status":"affected","lessThanOrEqual":"8.7.1","versionType":"semver"},{"version":"8.7.0","status":"affected","lessThanOrEqual":"8.7.0","versionType":"semver"},{"version":"8.6.0","status":"affected","lessThanOrEqual":"8.6.0","versionType":"semver"},{"version":"8.5.0","status":"affected","lessThanOrEqual":"8.5.0","versionType":"semver"},{"version":"8.4.0","status":"affected","lessThanOrEqual":"8.4.0","versionType":"semver"},{"version":"8.3.0","status":"affected","lessThanOrEqual":"8.3.0","versionType":"semver"},{"version":"8.2.1","status":"affected","lessThanOrEqual":"8.2.1","versionType":"semver"},{"version":"8.2.0","status":"affected","lessThanOrEqual":"8.2.0","versionType":"semver"},{"version":"8.1.2","status":"affected","lessThanOrEqual":"8.1.2","versionType":"semver"},{"version":"8.1.1","status":"affected","lessThanOrEqual":"8.1.1","versionType":"semver"},{"version":"8.1.0","status":"affected","lessThanOrEqual":"8.1.0","versionType":"semver"},{"version":"8.0.1","status":"affected","lessThanOrEqual":"8.0.1","versionType":"semver"},{"version":"8.0.0","status":"affected","lessThanOrEqual":"8.0.0","versionType":"semver"},{"version":"7.88.1","status":"affected","lessThanOrEqual":"7.88.1","versionType":"semver"},{"version":"7.88.0","status":"affected","lessThanOrEqual":"7.88.0","versionType":"semver"},{"version":"7.87.0","status":"affected","lessThanOrEqual":"7.87.0","versionType":"semver"},{"version":"7.86.0","status":"affected","lessThanOrEqual":"7.86.0","versionType":"semver"},{"version":"7.85.0","status":"affected","lessThanOrEqual":"7.85.0","versionType":"semver"},{"version":"7.84.0","status":"affected","lessThanOrEqual":"7.84.0","versionType":"semver"},{"version":"7.83.1","status":"affected","lessThanOrEqual":"7.83.1","versionType":"semver"},{"version":"7.83.0","status":"affected","lessThanOrEqual":"7.83.0","versionType":"semver"},{"version":"7.82.0","status":"affected","lessThanOrEqual":"7.82.0","versionType":"semver"},{"version":"7.81.0","status":"affected","lessThanOrEqual":"7.81.0","versionType":"semver"},{"version":"7.80.0","status":"affected","lessThanOrEqual":"7.80.0","versionType":"semver"},{"version":"7.79.1","status":"affected","lessThanOrEqual":"7.79.1","versionType":"semver"},{"version":"7.79.0","status":"affected","lessThanOrEqual":"7.79.0","versionType":"semver"},{"version":"7.78.0","status":"affected","lessThanOrEqual":"7.78.0","versionType":"semver"},{"version":"7.77.0","status":"affected","lessThanOrEqual":"7.77.0","versionType":"semver"},{"version":"7.76.1","status":"affected","lessThanOrEqual":"7.76.1","versionType":"semver"},{"version":"7.76.0","status":"affected","lessThanOrEqual":"7.76.0","versionType":"semver"},{"version":"7.75.0","status":"affected","lessThanOrEqual":"7.75.0","versionType":"semver"}]}],"references":[{"url":"https://curl.se/docs/CVE-2026-86409.json","name":"json"},{"url":"https://curl.se/docs/CVE-2026-86409.html","name":"www"},{"url":"https://hackerone.com/reports/3973135","name":"issue"}],"problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-201 Information Exposure Through Sent Data"}]}],"providerMetadata":{"shortName":"curl","orgId":"2499f714-1537-4658-8207-48ae4bb9eae9","dateUpdated":"2026-10-20T19:57:01.794Z"},"credits":[{"lang":"en","value":"Stanislav Fort (Aisle Research)","type":"finder"},{"lang":"en","value":"Viktor Szakats","type":"remediation developer"}]},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://hackerone.com/reports/3973135","tags":["exploit"]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":8.1,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"HIGH","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-10-29T18:33:46.064413Z","id":"CVE-2026-86409","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-201","type":"CWE","lang":"en","description":"CWE-201 Insertion of Sensitive Information Into Sent Data"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-29T18:33:49.983Z"}}]}}}