Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.41% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-113779High confidence
pfSense REST API package Vulnerable to Privilege Escalation via Scoped HA Settings Sync Permission
pfrest · pfSense-pkg-RESTAPI
Official source article: GitHub GHSA-8Q8G-9F77-8G8G ↗. Check the applicable product and release in the original source.
8.8HighCVSS 3.1
Within 7 days
Fix not verifiedHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs pfrest pfSense-pkg-RESTAPI and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
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.
What
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
Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.
What
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
Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Deserialization of Untrusted Data → gain additional privileges
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-502 ↗
CWE-502: Deserialization of Untrusted Data. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- pfSense-pkg-RESTAPI: < 2.9.0
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 21 Oct 2026 · Last source change 21 Oct 2026, 15:47 UTC · CWE-502 · Deserialization of Untrusted Data
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-10-22
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-107283
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-107283 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-107283"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.