Privilege escalation in pfSense REST API package through HA sync
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-502.
Summary
The pfSense REST API package (pfSense-pkg-RESTAPI) before version 2.9.0 lets authenticated accounts holding the dedicated settings sync permission modify REST API configuration secrets. A non-administrative user with that permission can gain full administrator privileges.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
The pfSense REST API package is an unofficial, open-source REST and GraphQL API for pfSense CE and pfSense Plus firewalls. A privilege escalation vulnerability in pfSense-pkg-RESTAPI prior to version 2.9.0 allows authenticated accounts holding the dedicated settings sync permission to modify REST API configuration secrets. This enables a non-administrative user to elevate their privileges to a full administrator. pfSense-pkg-RESTAPI 2.9.0 patches the issue. Access to the HA settings sync endpoint now strictly requires full administrative privileges (`page-all`). The sub-administrative sync privilege has been removed in versions v2.9.0 and later. In addition to correcting the access control boundary, version 2.9.0 includes the following hardening measures: opt-in default and format and validation modernization. As a workaround, one may mitigate exposure by taking either or all of the following steps. Revoke Scoped Permissions: Remove the `api-v2-system-restapi-settings-sync-post` privilege from all non-administrative users. Apply ACLs: Configure REST API Access Control Lists (ACLs) and/or firewall rules to restrict access to API endpoints exclusively to trusted administrator and HA peer IP addresses.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Update pfSense-pkg-RESTAPI to version 2.9.0, which requires full administrative privileges (page-all) for the HA settings sync endpoint and removes the sub-administrative sync privilege. Until the update is applied, remove the api-v2-system-restapi-settings-sync-post privilege from non-administrative users or restrict REST API access to trusted administrator and HA peer IP addresses using ACLs or firewall rules.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA pfSense-pkg-RESTAPI (pfrest) Fixed in 2.9.0
Timeline
- 2026-10-21 Threatist record created from CVE-2026-113779
- 2026-10-21 CISA SSVC decision points changed
- 2026-10-21 Priority changed: MEDIUM → LOW
- 2026-10-23 Priority changed: LOW → MEDIUM
References
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences