CVE-2026-33540 (GCVE-0-2026-33540)

Vulnerability from cvelistv5 – Published: 2026-04-06 14:55 – Updated: 2026-04-06 15:04
VLAI
Title
Distribution affected by pull-through cache credential exfiltration via www-authenticate bearer realm
Summary
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.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-06 15:04 UTC
CWE
  • CWE-918 - Server-Side Request Forgery (SSRF)
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7606 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
distribution distribution Affected: < 3.1.0
guessed Create a notification for this product.
Show details on NVD website
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