{"id":"CVE-2026-115693","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-115693","generatedAt":"2026-10-28T08:11:02.071Z","title":"Improper Certificate Validation vulnerability in hackney_ssl in benoitc hackney allows an on-path attacker to impersonate a server pinned to a private certificate authority via a certificate chain that ends in a publicly trusted root. hackney adds…","description":"Improper Certificate Validation vulnerability in hackney_ssl in benoitc hackney allows an on-path attacker to impersonate a server pinned to a private certificate authority via a certificate chain that ends in a publicly trusted root. hackney adds {partial_chain, fun hackney_ssl:partial_chain/1} to every verify_peer configuration. The callback returns any certificate in the peer chain whose public key matches a root in the bundled certifi store as the trust anchor, and OTP honours that callback over the configured cacerts. hackney_ssl:merge_ssl_opts/3 kept the callback when the caller replaced the trust store with cacerts or cacertfile in ssl_options, so a connection pinned to a private CA still accepted any chain that carried a publicly trusted root.\n\nThe hostname check still applies, so the attacker needs a publicly trusted certificate for the pinned hostname.\n\nThis issue affects hackney: from 1.24.0 before 4.9.0.","published":"2026-10-26T14:16:32.000Z","lastModified":"2026-10-26T16:59:16.000Z","status":"Awaiting Analysis","sourceIdentifier":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","cvss":{"version":"4.0","score":9.1,"severity":"CRITICAL","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-295"],"affected":[],"epss":{"score":0.00267,"percentile":0.1876,"date":"2026-10-27","history":[{"date":"2026-10-27","score":0.00267,"percentile":0.1876}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-26T14:16:32.000Z","detail":{"score":"9.1","severity":"CRITICAL","publishedAt":"2026-10-26T14:16:31.853Z"},"summary":"New CVE, critical severity (CVSS 9.1)."}],"references":[{"url":"https://cna.erlef.org/cves/CVE-2026-115693.html","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/benoitc/hackney/commit/915eb5737e9c489d8fc22eec8cdae30e9b027be4","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/benoitc/hackney/commit/d8a9afcf5c3849904274e2eba1df56c63d1a1a0c","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/benoitc/hackney/pull/978","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/benoitc/hackney/releases/tag/4.9.0","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-115693","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-115693","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}