CVE-2026-56855 Affecting linkerd2-controller package, versions <26.8.4-r2
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-MINIMOSLATEST-LINKERD2CONTROLLER-19534730
- published5 Sept 2026
- disclosed2 Sept 2026
Introduced: 2 Sep 2026
NewCVE-2026-56855 (opens in a new tab)How to fix?
Upgrade Minimos:latest linkerd2-controller to version 26.8.4-r2 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream linkerd2-controller package and not the linkerd2-controller package as distributed by Minimos.
See How to fix? for Minimos:latest relevant fixed versions and status.
Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.