{"id":"CVE-2026-11856","title":"Successfully using libcurl to do a transfer to a specific HTTP origin\n(`hostA`) with **Digest** authentication and then changing the origin to a\ndifferent one (`hostB`) for a second transfer, reusing the same handle, makes\nlibcurl wrongl…","summary":"Successfully using libcurl to do a transfer to a specific HTTP origin\n(`hostA`) with **Digest** authentication and then changing the origin to a\ndifferent one (`hostB`) for a second transfer, reusing the same handle, makes\nlibcurl wrongl…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-294","CWE-201"],"vendor":"haxx","product":"curl","affected":["curl >= 7.10.6, < 8.21.0"],"patched":["curl 8.21.0"],"published":"2026-07-03","updated":"2026-09-15","sourceUpdated":"2026-09-15T07:16:25.870","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-11856","references":[{"url":"https://curl.se/docs/CVE-2026-11856.html","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://curl.se/docs/CVE-2026-11856.json","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://hackerone.com/reports/3793260","label":"2499f714-1537-4658-8207-48ae4bb9eae9"},{"url":"https://hackerone.com/reports/3793260","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-11856.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-11856"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2496767"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-11856"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-11856"},{"url":"https://access.redhat.com/errata/RHSA-2026:69125"},{"url":"https://access.redhat.com/errata/RHSA-2026:34975"},{"url":"https://access.redhat.com/errata/RHSA-2026:29017"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat","score-dispute"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"total","timestamp":"2026-07-06T18:22:46.260282Z"},"epss":0.00688,"epssPercentile":0.51293,"ingestedAt":"2026-07-04T04:55:39.425Z","scores":{"nvd":9.8,"vendor":6.5},"slug":"CVE-2026-11856","body":"## Overview\n\nSuccessfully using libcurl to do a transfer to a specific HTTP origin\n(`hostA`) with **Digest** authentication and then changing the origin to a\ndifferent one (`hostB`) for a second transfer, reusing the same handle, makes\nlibcurl wrongly pass on the `Authorization:` header field meant for `hostA`,\nto `hostB`.\n\n## Affected\n\n- `curl >= 7.10.6, < 8.21.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `curl 8.21.0`\n\n## Vendor advisories\n\n- **RHSA-2026:69125** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69125)\n- **RHSA-2026:34975** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:34975)\n- **RHSA-2026:29017** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:29017)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 8, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-11856.json)","depth":"abyssal","depthScore":66,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":203484,"id":"CVE-2026-11856","ts":1789457645717,"field":"exploit_available","old":"false","new":"true"},{"seq":203483,"id":"CVE-2026-11856","ts":1789457645717,"field":"cvss","old":null,"new":"9.8"},{"seq":203482,"id":"CVE-2026-11856","ts":1789457645717,"field":"severity","old":"none","new":"critical"}]}