{"cvss":9.1,"datePublished":"2026-07-03T07:16:25.123","dateUpdated":"2026-09-15T07:16:33.157","description":"When reusing a libcurl handle for sequential transfers driven by\nenvironment-variable proxy configuration, libcurl fails to clear the proxy\nauthentication state between requests. Specifically, if the initial transfer\nauthenticates against `proxyA` using Digest auth, a subsequent transfer routed\nthrough `proxyB` erroneously leaks the `Proxy-Authorization:` header intended\nsolely for `proxyA`.","id":"CVE-2026-8927","raw":{"affected":[{"affectedData":[{"defaultStatus":"unaffected","product":"curl","vendor":"curl","versions":[{"lessThan":"8.14.2","status":"affected","version":"7.12.0","versionType":"semver"},{"lessThan":"8.16.1","status":"affected","version":"8.15.0","versionType":"semver"},{"lessThan":"8.20.1","status":"affected","version":"8.17.0","versionType":"semver"}]},{"defaultStatus":"unaffected","product":"curl","repo":"https://github.com/curl/curl.git","vendor":"curl","versions":[{"lessThan":"5c225384b8d52c67ce8259c6e4203bc57aacb567","status":"affected","version":"fc6eff13b5414caf6edf22d73a3239e074a04216","versionType":"git"}]},{"defaultStatus":"unaffected","product":"curl","vendor":"curl","versions":[{"status":"affected","version":"8.20.0"},{"status":"affected","version":"8.19.0"},{"status":"affected","version":"8.18.0"},{"status":"affected","version":"8.17.0"},{"status":"affected","version":"8.16.0"},{"status":"affected","version":"8.15.0"},{"status":"affected","version":"8.14.1"},{"status":"affected","version":"8.14.0"},{"status":"affected","version":"8.13.0"},{"status":"affected","version":"8.12.1"},{"status":"affected","version":"8.12.0"},{"status":"affected","version":"8.11.1"},{"status":"affected","version":"8.11.0"},{"status":"affected","version":"8.10.1"},{"status":"affected","version":"8.10.0"},{"status":"affected","version":"8.9.1"},{"status":"affected","version":"8.9.0"},{"status":"affected","version":"8.8.0"},{"status":"affected","version":"8.7.1"},{"status":"affected","version":"8.7.0"},{"status":"affected","version":"8.6.0"},{"status":"affected","version":"8.5.0"},{"status":"affected","version":"8.4.0"},{"status":"affected","version":"8.3.0"},{"status":"affected","version":"8.2.1"},{"status":"affected","version":"8.2.0"},{"status":"affected","version":"8.1.2"},{"status":"affected","version":"8.1.1"},{"status":"affected","version":"8.1.0"},{"status":"affected","version":"8.0.1"},{"status":"affected","version":"8.0.0"},{"status":"affected","version":"7.88.1"},{"status":"affected","version":"7.88.0"},{"status":"affected","version":"7.87.0"},{"status":"affected","version":"7.86.0"},{"status":"affected","version":"7.85.0"},{"status":"affected","version":"7.84.0"},{"status":"affected","version":"7.83.1"},{"status":"affected","version":"7.83.0"},{"status":"affected","version":"7.82.0"},{"status":"affected","version":"7.81.0"},{"status":"affected","version":"7.80.0"},{"status":"affected","version":"7.79.1"},{"status":"affected","version":"7.79.0"},{"status":"affected","version":"7.78.0"},{"status":"affected","version":"7.77.0"},{"status":"affected","version":"7.76.1"},{"status":"affected","version":"7.76.0"},{"status":"affected","version":"7.75.0"},{"status":"affected","version":"7.74.0"},{"status":"affected","version":"7.73.0"},{"status":"affected","version":"7.72.0"},{"status":"affected","version":"7.71.1"},{"status":"affected","version":"7.71.0"},{"status":"affected","version":"7.70.0"},{"status":"affected","version":"7.69.1"},{"status":"affected","version":"7.69.0"},{"status":"affected","version":"7.68.0"},{"status":"affected","version":"7.67.0"},{"status":"affected","version":"7.66.0"},{"status":"affected","version":"7.65.3"},{"status":"affected","version":"7.65.2"},{"status":"affected","version":"7.65.1"},{"status":"affected","version":"7.65.0"},{"status":"affected","version":"7.64.1"},{"status":"affected","version":"7.64.0"},{"status":"affected","version":"7.63.0"},{"status":"affected","version":"7.62.0"},{"status":"affected","version":"7.61.1"},{"status":"affected","version":"7.61.0"},{"status":"affected","version":"7.60.0"},{"status":"affected","version":"7.59.0"},{"status":"affected","version":"7.58.0"},{"status":"affected","version":"7.57.0"},{"status":"affected","version":"7.56.1"},{"status":"affected","version":"7.56.0"},{"status":"affected","version":"7.55.1"},{"status":"affected","version":"7.55.0"},{"status":"affected","version":"7.54.1"},{"status":"affected","version":"7.54.0"},{"status":"affected","version":"7.53.1"},{"status":"affected","version":"7.53.0"},{"status":"affected","version":"7.52.1"},{"status":"affected","version":"7.52.0"},{"status":"affected","version":"7.51.0"},{"status":"affected","version":"7.50.3"},{"status":"affected","version":"7.50.2"},{"status":"affected","version":"7.50.1"},{"status":"affected","version":"7.50.0"},{"status":"affected","version":"7.49.1"},{"status":"affected","version":"7.49.0"},{"status":"affected","version":"7.48.0"},{"status":"affected","version":"7.47.1"},{"status":"affected","version":"7.47.0"},{"status":"affected","version":"7.46.0"},{"status":"affected","version":"7.45.0"},{"status":"affected","version":"7.44.0"},{"status":"affected","version":"7.43.0"},{"status":"affected","version":"7.42.1"},{"status":"affected","version":"7.42.0"},{"status":"affected","version":"7.41.0"},{"status":"affected","version":"7.40.0"},{"status":"affected","version":"7.39.0"},{"status":"affected","version":"7.38.0"},{"status":"a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reusing a libcurl handle for sequential transfers driven by\nenvironment-variable proxy configuration, libcurl fails to clear the proxy\nauthentication state between requests. Specifically, if the initial transfer\nauthenticates against `proxyA` using Digest auth, a subsequent transfer routed\nthrough `proxyB` erroneously leaks the `Proxy-Authorization:` header intended\nsolely for `proxyA`."}],"id":"CVE-2026-8927","lastModified":"2026-09-15T07:16:33.157","metrics":{"cvssMetricV31":[{"cvssData":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":9.1,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"exploitabilityScore":3.9,"impactScore":5.2,"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary"}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"id":"CVE-2026-8927","options":[{"exploitation":"poc"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","timestamp":"2026-07-06T17:00:13.489405Z","version":"2.0.3"}}]},"published":"2026-07-03T07:16:25.123","references":[{"source":"2499f714-1537-4658-8207-48ae4bb9eae9","tags":["Patch","Vendor Advisory"],"url":"https://curl.se/docs/CVE-2026-8927.html"},{"source":"2499f714-1537-4658-8207-48ae4bb9eae9","tags":["Vendor Advisory"],"url":"https://curl.se/docs/CVE-2026-8927.json"},{"source":"2499f714-1537-4658-8207-48ae4bb9eae9","tags":["Exploit","Issue Tracking","Third Party Advisory"],"url":"https://hackerone.com/reports/3744543"},{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":["Exploit","Issue Tracking","Third Party Advisory"],"url":"https://hackerone.com/reports/3744543"}],"sourceIdentifier":"2499f714-1537-4658-8207-48ae4bb9eae9","vulnStatus":"Modified","weaknesses":[{"description":[{"lang":"en","value":"CWE-294"}],"source":"2499f714-1537-4658-8207-48ae4bb9eae9","type":"Secondary"},{"description":[{"lang":"en","value":"CWE-294"}],"source":"nvd@nist.gov","type":"Primary"}]},"severity":"CRITICAL","source":"nvd","title":"When reusing a libcurl handle for sequential transfers driven by\nenvironment-variable proxy configuration, libcurl fa..."}