CVE-2026-119425 json
OPNsense 26.1.6 through 26.7.7 Captive Portal Session Takeover via Forged ARP
published 2026-10-30 10 d ago modified 2026-10-30 9 d ago also EUVD-2026-113805
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 24%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- opnsense opnsense 26.7.3
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 10 d ago
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.3 | 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 |
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| CNA | 4.0 | 5.3 | 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 |
Affected products
- opnsense core
Classification
- Weakness
-
- CWE-290 Authentication Bypass by Spoofing
References
-
github.com
/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55
patch
-
github.com
/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834
patch
-
github.com
/opnsense/core/security/advisories/GHSA-864r-q4j5-5mjq
vendor-advisory
-
github.com
/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78
technical-description
-
abraxaslabs.tech
/research/opnsense-captive-lastseen-roam
third-party-advisory
-
github.com
/opnsense/core
product
-
vulncheck.com
/advisories/opnsense-26.1.6-through-26.7.7-captive-portal-session-takeover-via-forged-arp
third-party-advisory
Sources
- CVE List CVE-2026-119425
- NVD CVE-2026-119425
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.