CVE-2026-36499: Medium severity Open vSwitch Open vSwitch vulnerability
A missing upper-bound check in the udpifsetthreads() function of Open vSwitch v3.6.90 allows an attacker with OVSDB write access to request an excessive number of handler or revalidation threads. This can cause a denial of service (DoS) via resource exhaustion.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Remove or restrict OVSDB write privileges so that only trusted administrators may perform writes to OVSDB; ensure unprivileged users and services cannot modify OVSDB values (including thread count settings).
Open vSwitch (OVSDB) OVSDB write access = restricted to trusted administrators - Compensating control
Restrict network access to the OVSDB management interface to trusted hosts/networks using firewall rules or ACLs (limit which systems can reach and write to OVSDB).
- Operational
Monitor OVSDB for changes that set handler or revalidation thread counts to excessive values; alert on anomalous increases and, if resource exhaustion occurs, revert the change and restart affected Open vSwitch daemons to recover service.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-36499?
CVE-2026-36499 has a medium severity rating of 6.5 according to the CVSS 3.1 metrics.
How do I fix CVE-2026-36499?
To mitigate CVE-2026-36499, ensure that you apply the latest patch provided by Open vSwitch addressing the missing upper-bound check.
What are the potential impacts of CVE-2026-36499?
CVE-2026-36499 can lead to a denial of service (DoS) due to resource exhaustion if exploited by unauthorized users with OVSDB write access.
What is the affected software for CVE-2026-36499?
CVE-2026-36499 affects Open vSwitch version 3.6.90.
Who can exploit CVE-2026-36499?
Only an attacker with OVSDB write access can exploit CVE-2026-36499 to request an excessive number of handler or revalidation threads.