CVE-2026-119425OPNsense 26.1.6 through 26.7.7 Captive Portal Session Takeover via Forged ARP
- 5.3MediumCVSS base score
- 0.31%Exploitation in 30 daysEPSS · top 75% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in the captive portal roaming feature that lets unauthenticated attackers hijack authorized client sessions by spoofing unauthenticated MAC-to-IP observations. Attackers on the same Layer-2 segment can send forged gratuitous ARP replies binding their IP to a victim's MAC, gaining portal access with traffic attributed to the victim.
Timeline
ID reserved
By VulnCheck
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | Medium5.3 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N |
| VulnCheckCNA (assigner) | 3.1 | Medium5.4 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| NVDNVD · Deferred | 4.0 | Medium5.3 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.31% · top 75% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
References
References7
- GitHub Security Advisory (GHSA-864r-q4j5-5mjq) (opens in a new tab)vendor-advisory
- Incomplete fix (opens in a new tab)patch
- Incomplete fix (stable/26.7) (opens in a new tab)patch
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78 (opens in a new tab)technical-description
- https://abraxaslabs.tech/research/opnsense-captive-lastseen-roam (opens in a new tab)third-party-advisory
- https://github.com/opnsense/core (opens in a new tab)product
- VulnCheck Advisory: OPNsense 26.1.6 through 26.7.7 Captive Portal Session Takeover via Forged ARP (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-113805 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-119425)Record last updated .