CVE-2026-49457Public exploitNetwork attack vectorHinoki check available

Server impersonation via omitted TLS certificate checks

Published Aug 14, 2026 · Updated Aug 14, 2026

Improper certificate validation in erlang_quic before 1.4.4 allows man-in-the-middle attackers to impersonate QUIC and HTTP/3 servers. The client skips the CertificateVerify signature, certificate-chain, and hostname checks, making its verify setting ineffective. A network-path position and certificate-based handshake are required; PSK-authenticated resumptions remain unaffected, while intercepted connections lose confidentiality and integrity.

CVSS severity9.1
Critical
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper certificate validation in erlang_quic before 1.4.4 allows man-in-the-middle attackers to impersonate QUIC and HTTP/3 servers. The client skips the CertificateVerify signature, certificate-chain, and hostname checks, making its verify setting ineffective. A network-path position and certificate-based handshake are required; PSK-authenticated resumptions remain unaffected, while intercepted connections lose confidentiality and integrity.

The record

CVE
CVE-2026-49457
Published
Aug 14, 2026
Updated
Aug 14, 2026
Vendor
Benoit Chesneau
Product
erlang_quic
Classifications
CWE-297, CWE-295, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.4.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Benoit Chesneau · erlang_quicversion=< 1.4.4

Published CVSS scores

9.1GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-297Improper Validation of Certificate with Host Mismatch
CWE-295Improper Certificate Validation
T1557Adversary-in-the-Middle

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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