CVE-2026-41207Network attack vector

Predictable AEAD keys via zero-filled HPKE outputs

Published Jun 4, 2026 · Updated Jun 4, 2026

Cryptographic failure handling in Netty netty-incubator-codec-ohttp before 0.0.21.Final allows remote attackers to derive predictable AEAD keys. The BoringSSL JNI wrappers for HKDF_expand and EVP_HPKE_CTX_export return zero-filled arrays after native failures, and OHttpCrypto.createResponseAEAD consumes the export as response key material instead of rejecting it. An unauthenticated network path must reach a failing OHTTP cryptographic operation; the resulting deterministic key compromises response confidentiality and integrity without a reported service interruption.

CVSS severity6.9
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic failure handling in Netty netty-incubator-codec-ohttp before 0.0.21.Final allows remote attackers to derive predictable AEAD keys. The BoringSSL JNI wrappers for HKDF_expand and EVP_HPKE_CTX_export return zero-filled arrays after native failures, and OHttpCrypto.createResponseAEAD consumes the export as response key material instead of rejecting it. An unauthenticated network path must reach a failing OHTTP cryptographic operation; the resulting deterministic key compromises response confidentiality and integrity without a reported service interruption.

The record

CVE
CVE-2026-41207
Published
Jun 4, 2026
Updated
Jun 4, 2026
Vendor
The Netty Project
Product
Netty/Incubator/Codec/OHTTP
Classifications
CWE-330
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 4, 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=< 0.0.21.Final

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Netty Project · Netty/Incubator/Codec/OHTTPversion=< 0.0.21.Final

Published CVSS scores

6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
5.3NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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