Server-Side Request Forgery (SSRF) Affecting zot package, versions <2.1.15-r8


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.04% (11th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-ZOT-15966103
  • published10 Apr 2026
  • disclosed6 Apr 2026

Introduced: 6 Apr 2026

NewCVE-2026-33540  (opens in a new tab)
CWE-918  (opens in a new tab)

How to fix?

Upgrade Chainguard zot to version 2.1.15-r8 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream zot package and not the zot package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, in pull-through cache mode, distribution discovers token auth endpoints by parsing WWW-Authenticate challenges returned by the configured upstream registry. The realm URL from a bearer challenge is used without validating that it matches the upstream registry host. As a result, an attacker-controlled upstream (or an attacker with MitM position to the upstream) can cause distribution to send the configured upstream credentials via basic auth to an attacker-controlled realm URL. This vulnerability is fixed in 3.1.0.

CVSS Base Scores

version 3.1