CVE-2022-21654Network attack vector

Authentication bypass via incomplete TLS session digest

Published Feb 22, 2022 · Updated Apr 23, 2025

Improper mTLS session validation in affected Envoy releases allows remote authenticated users to retain unauthorized resource access. DefaultCertValidator::updateDigestForSessionId omits certificate-validation settings from the TLS session-context digest, so policy changes do not invalidate resumable sessions. Exploitation requires a session established under the old policy and a later certificate-validation change, enabling access that the new policy denies.

CVSS severity7.4
High
EPSS probability1.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper mTLS session validation in affected Envoy releases allows remote authenticated users to retain unauthorized resource access. DefaultCertValidator::updateDigestForSessionId omits certificate-validation settings from the TLS session-context digest, so policy changes do not invalidate resumable sessions. Exploitation requires a session established under the old policy and a later certificate-validation change, enabling access that the new policy denies.

The record

CVE
CVE-2022-21654
Published
Feb 22, 2022
Updated
Apr 23, 2025
Vendor
Envoy Proxy
Product
Envoy
Classifications
CWE-367, CWE-295
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record 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=>= 1.19.0, < 1.19.3
  2. Affected versionversion=>= 1.20.0, < 1.20.2
  3. Affected versionversion=>= 1.21.0, < 1.21.1
  4. Affected versionversion=>= 1.7.0, < 1.18.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Envoy Proxy · Envoyversion=>= 1.19.0, < 1.19.3; version=>= 1.20.0, < 1.20.2; version=>= 1.21.0, < 1.21.1; version=>= 1.7.0, < 1.18.6

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.4GitHub CNACVSS:3.1/AV:N/AC:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
CWE-295Improper Certificate Validation

Public exploit references

No public exploit references are available in this record.

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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