CVE-2026-33117Network attack vector

Integrity bypass via self-comparison of authentication tag

Published May 12, 2026 · Updated May 12, 2026

Improper authentication in Azure Key Vault Keys for Java before 4.10.6 allows remote attackers to bypass encrypted-data integrity checks. AesCbcHmacSha2Decryptor.doFinal compares the computed authentication tag with itself instead of the received tag, so altered ciphertext is accepted. Reachability requires an application to process attacker-controlled ciphertext with local cryptography; Key Vault service operations are unaffected.

CVSS severity9.1
Critical
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Azure Key Vault Keys for Java before 4.10.6 allows remote attackers to bypass encrypted-data integrity checks. AesCbcHmacSha2Decryptor.doFinal compares the computed authentication tag with itself instead of the received tag, so altered ciphertext is accepted. Reachability requires an application to process attacker-controlled ciphertext with local cryptography; Key Vault service operations are unaffected.

The record

CVE
CVE-2026-33117
Published
May 12, 2026
Updated
May 12, 2026
Vendor
Microsoft
Product
Azure SDK for Java
Classifications
CWE-287, CWE-347, T1565
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 12, 2026CVE publishedPublication date reported by the CVE source.
  2. May 12, 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=1.0.0 <4.10.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Azure SDK for Javaversion=1.0.0 <4.10.6

Published CVSS scores

9.1GitHub Advisory DatabaseCVSS: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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-347Improper Verification of Cryptographic Signature
T1565Data Manipulation

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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