CVE-2026-49457

QUIC has Broken TLS verification

Published Aug 14, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
erlang_quic is a pure Erlang QUIC implementation. Prior to version 1.4.4, the QUIC client did not authenticate the server during the TLS 1.3 handshake. The CertificateVerify signature was not checked, the certificate chain was not validated, and the hostname was not compared against the certificate, so `verify` was effectively a no-op on the client. A man-in-the-middle on the network path could present any certificate and impersonate any server, defeating the confidentiality and integrity of the connection. HTTP/3 uses the same client and was equally affected. Handshakes authenticated by a PSK (session resumption) are not affected, because the peer is authenticated by the PSK binder and no certificate is sent. This is fixed in 1.4.4. The client now verifies the CertificateVerify signature, validates the certificate chain against the trust store (`cacerts` option, the operating system store by default), and checks the hostname. Client `verify` now defaults to on; set `verify => false` to accept any certificate (for example a self-signed test server). No known workarounds are available before 1.4.4. `verify => true` had no effect, and inspecting the certificate after connecting does not help because without the signature check the peer is never proven to own the certificate it presents.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-2r8v-p65x-3663 QUIC has Broken TLS verification
History
Type Values Removed Values Added
First Time appeared Benoitc
Benoitc erlang Quic
Vendors & Products Benoitc
Benoitc erlang Quic
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description erlang_quic is a pure Erlang QUIC implementation. Prior to version 1.4.4, the QUIC client did not authenticate the server during the TLS 1.3 handshake. The CertificateVerify signature was not checked, the certificate chain was not validated, and the hostname was not compared against the certificate, so `verify` was effectively a no-op on the client. A man-in-the-middle on the network path could present any certificate and impersonate any server, defeating the confidentiality and integrity of the connection. HTTP/3 uses the same client and was equally affected. Handshakes authenticated by a PSK (session resumption) are not affected, because the peer is authenticated by the PSK binder and no certificate is sent. This is fixed in 1.4.4. The client now verifies the CertificateVerify signature, validates the certificate chain against the trust store (`cacerts` option, the operating system store by default), and checks the hostname. Client `verify` now defaults to on; set `verify => false` to accept any certificate (for example a self-signed test server). No known workarounds are available before 1.4.4. `verify => true` had no effect, and inspecting the certificate after connecting does not help because without the signature check the peer is never proven to own the certificate it presents.
Title QUIC has Broken TLS verification
Weaknesses CWE-295
CWE-297
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 14, 2026, 7:30 PM
Reserved
May 30, 2026, 2:43 AM
Status
Deferred
Published
Aug 14, 2026, 7:17 PM
Modified
Sep 18, 2026, 8:09 PM