CVE-2026-42602 azureauthextension Authenticate method does not validate bearer tokens, allowing auth bypass via replay
Attackers can bypass authentication in OpenTelemetry collectors by replaying valid Azure tokens for any scope, gaining unauthorized access to receivers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42602?
CVE-2026-42602 is a high-severity authentication bypass vulnerability in open-telemetry opentelemetry-collector-contrib, published on 13 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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 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).
Which versions are affected by CVE-2026-42602?
3 open source packages ship an affected version, including github.com/open-telemetry/opentelemetry-collector-contrib/extension/azureauthextension. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/open-telemetry/opentelemetry-collector-contrib/extension/azureauthextension Go | From 0.124.0 to 0.150.0 | None |
github.com/open-telemetry/opentelemetry-collector-contrib/extension/azureauthextension Go | From 0.124.0 to 0.150.0 | None |
github.com/open-telemetry/opentelemetry-collector-contrib/extension/azureauthextension Go | From 0.124.0 | 0.151.0 |
Products include Opentelemetry Opentelemetry Collector Contrib.
How do I fix CVE-2026-42602?
Upgrade github.com/open-telemetry/opentelemetry-collector-contrib/extension/azureauthextension to 0.151.0 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-42602 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42602 exists.
Sources
Also known as GHSA-pjv4-3c63-699f, GO-2026-5544, MINI-24cw-5m99-p29q, MINI-7hpc-cqrm-4fg4, MINI-c286-jr9c-h98x, MINI-x4g4-rmjv-6c9c.