CVE-2026-71490 OPNsense: Direct comma-separated user privileges bypass OPNsense MVC read-only write protection
Attackers with specific user privileges can bypass read-only restrictions to modify firewall configuration via MVC APIs.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-71490?
CVE-2026-71490 is a high-severity authentication bypass vulnerability in opnsense core, published on 15 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.11, OPNsense\Core\ACL::hasPrivilege() appends a directly assigned comma-separated <priv> value as one string and then uses an exact comparison when checking user-config-readonly. A user directly assigned both a component write privilege and user-config-readonly can therefore be treated as lacking the read-only restriction, and MVC APIs protected by throwReadOnly() can persist configuration changes for that component. Group privileges are not affected by the same parser flaw because the group path already splits comma-separated values. This issue is fixed in version 26.1.11.
Weakness: CWE-863
Which versions are affected by CVE-2026-71490?
How do I fix CVE-2026-71490?
No fix has been published for CVE-2026-71490 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-71490 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-71490 exists.
Sources
Also known as GHSA-p9pr-782r-w2xw.