CVE-2026-42602
Published: 13 May 2026
Summary
CVE-2026-42602 is a high-severity Observable Timing Discrepancy (CWE-208) vulnerability in Opentelemetry Opentelemetry Collector Contrib. Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 12.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-30160
Vulnerability details
azureauthextension is the Azure Authenticator Extension. From 0.124.0 to 0.150.0, a server-side authentication bypass in azureauthextension allows any party who holds a single valid Azure access token for any scope the collector's configured identity can mint for to authenticate to…
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any OpenTelemetry receiver that uses auth: azure_auth. The extension's Authenticate method does not validate incoming bearer tokens as JWTs. Instead, it calls its own configured credential to obtain an access token and compares the client's token to the result with string equality — and the scope for that server-side token request is taken from the client-supplied Host header. As a result, a token minted for any Azure resource the service principal has ever been issued a token for (ARM, Graph, Key Vault, Storage, etc.) will authenticate to the collector if the attacker picks a matching Host. Tokens are replayable for the full issued lifetime (commonly several hours for managed identity tokens).
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Authentication bypass in publicly exposed OpenTelemetry receiver directly enables exploitation of a public-facing application via token replay and improper JWT validation.
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Detects unauthorized successful logons resulting from improper authentication implementations.
Requires authentication mechanisms on the wireless link, making improper authentication weaknesses harder to exploit.
Security awareness training instructs users on secure authentication practices and avoiding credential compromise.
Identity proofing requires collecting, validating, and verifying evidence to resolve claims to unique individuals, directly preventing insufficient proof of identity during account establishment.
Enforces unique device identification and authentication before any connection is established, directly mitigating improper authentication weaknesses.
Mandates unique identification and authentication of non-organizational users, directly mitigating improper authentication.
Requires unique identification and authentication of services before any communications, directly mitigating improper authentication.
Directly counters DNS response spoofing by requiring cryptographic origin authentication artifacts from the authoritative source.