distribution: Improper Access Control
CVE-2026-35172 is a high-severity improper access control vulnerability in distribution, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected distribution versions: < 3.1.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.47% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of distribution you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Distribution | distribution | < 3.1.0 | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.12 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.13 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.14 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.15 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.16 | Not specified in the record | Not stated |
| Red Hat | Red Hat Openshift Data Foundation 4.22 | Not specified in the record | Not stated |
| Red Hat | Multicluster Engine for Kubernetes | Not specified in the record | Not stated |
| Red Hat | Red Hat Advanced Cluster Management for Kubernetes 2 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CNA (github.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | CNA |
Official description
Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, distribution can restore read access in repo a after an explicit delete when storage.cache.blobdescriptor: redis and storage.delete.enabled: true are both enabled. The delete path clears the shared digest descriptor but leaves stale repo-scoped membership behind, so a later Stat or Get from repo b repopulates the shared descriptor and makes the deleted blob readable from repo a again. This vulnerability is fixed in 3.1.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- access.redhat.com/errata/RHSA-2026:23234
- access.redhat.com/errata/RHSA-2026:25045
- access.redhat.com/errata/RHSA-2026:26529
- access.redhat.com/errata/RHSA-2026:26543
- access.redhat.com/errata/RHSA-2026:28893
- access.redhat.com/errata/RHSA-2026:37387
- access.redhat.com/security/cve/CVE-2026-35172
- bugzilla.redhat.com/show_bug.cgi?id=2455571
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35172.json
Other vulnerabilities in distribution
- 7.5 High severity
Recent Improper Access Control vulnerabilities
- 10.0 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.1 High severity
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