CVE-2026-33540
Distribution is a toolkit to pack, ship, store, and deliver container content.
Published Apr 6, 2026 · updated Jun 17, 2026 · distribution project distribution
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.
Code
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No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Apr 6, 2026 · NIST NVD
Detected
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 ups
Jun 17, 2026 · NIST NVD
Updated
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 ups
Affected
- cpe distribution project/distributionversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-33540
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-33540
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
nvd.nist.gov