CVE-2026-115693

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. The hostname check still applies, so the attacker needs a publicly trusted certificate for the pinned hostname. This issue affects hackney: from 1.24.0 before 4.9.0.

CVSS

No CVSS.

References

Link	Resource
https://cna.erlef.org/cves/CVE-2026-115693.html
https://github.com/benoitc/hackney/commit/915eb5737e9c489d8fc22eec8cdae30e9b027be4
https://github.com/benoitc/hackney/commit/d8a9afcf5c3849904274e2eba1df56c63d1a1a0c
https://github.com/benoitc/hackney/pull/978
https://github.com/benoitc/hackney/releases/tag/4.9.0
https://osv.dev/vulnerability/EEF-CVE-2026-115693

Configurations

No configuration.

History

26 Oct 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-26 14:16

Updated : 2026-10-26 16:59

NVD link : CVE-2026-115693

Mitre link : CVE-2026-115693

CVE.ORG link : CVE-2026-115693

JSON object : View

Products Affected

No product.

CWE

CWE-295

Improper Certificate Validation

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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."}], "lastModified": "2026-10-26T16:59:16.113", "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}