Red Hat OpenStack Platform 18.0: Observable Timing Discrepancy
CVE-2026-83535 is a high-severity observable timing discrepancy vulnerability in Red Hat OpenStack Platform 18.0 from Red Hat, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.28% 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 Red Hat OpenStack Platform 18.0 you run against the affected versions below, and install the vendor's latest release.
- 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 |
|---|---|---|---|
| Red Hat | Red Hat OpenStack Platform 18.0 | 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
- HighSuccess depends on conditions outside the attacker's control.
- 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
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (redhat.com).
Official description
A flaw was found in openstack-network-exporter. When an operator configures user authentication but omits or misconfigures Transport Layer Security (TLS), the basic authentication mechanism is silently bypassed. This fail-open design allows an adjacent network attacker to access sensitive Open vSwitch (OVS) and Open Virtual Network (OVN) dataplane metrics without credentials. Consequently, an attacker can enumerate bridge names, port counters, OVN controller state, and host topology, leading to information disclosure.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Observable Timing Discrepancy
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
More Observable Timing Discrepancy vulnerabilities (CWE-208)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Red Hat OpenStack Platform 18.0
- 8.5 High severity
- 9.3 Critical severity
- 8.8 High severity
- 8.1 High severity
- 8.2 High severity
- 7.3 High severity
Recent Observable Timing Discrepancy vulnerabilities
- 8.2 High severity
- 9.2 Critical severity
- 9.8 Critical severity
- 7.4 High severity
- 7.5 High severity
- 7.5 High severity
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