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CVE-2026-119425medium5.4

OPNsense 26.1.6 through 26.7.7 Captive Portal Session Takeover via Forged ARP

Impact

OPNsense core versions 26.1.6 through 26.7.7 have an authentication bypass vulnerability in the captive portal roaming feature, allowing attackers on the same Layer-2 segment to hijack authorized client sessions by spoofing MAC-to-IP observations. Attackers can send forged ARP replies to gain portal access.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Affected packages

This source has no supported package-version data for matching. You can read the advisory here, but this record alone cannot power a dependency check.

Affected products

Vendor version evidence. Product records are separate from automatic dependency matching.

opnsense · VulnCheck

core

1 range
VulnCheck version evidence

Package identity

pkg:github/opnsense/core

Identity supplied by VulnCheck. Version matching requires compatible range evidence.

Compare with this publisher’s ranges. This does not inspect your installation.

affected

26.1.6 → through 26.7.7

semver versions

unaffected

unknown

Other versions: unaffected

Original source 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.

Inside the record

Evidence available

Package identity
Version evidence
Remediation guidance · not supplied
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-119425

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-290 ↗

Authentication Bypass by Spoofing

VulnCheck

Related →

Environment requirements

These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.

VulnCheck · platform conditions

Any condition may hold

Vulnerable product

cpe:2.3:a:opnsense:opnsense:*:*:*:*:*:*:*:*

From (inclusive): 26.1.6

Through (inclusive): 26.7.7

Original applicability statements
[
  {
    "nodes": [
      {
        "operator": "OR",
        "negate": false,
        "cpeMatch": [
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:opnsense:opnsense:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "26.1.6",
            "versionEndIncluding": "26.7.7"
          }
        ]
      }
    ]
  }
]
Contributing organizations · 2
VulnCheck

Assigning organization

2026-10-30
CISA-ADP

Additional data publisher

2026-10-30

What changed

Follow changes
  1. CVE · CVE-2026-119425

    Observed 2026-10-30T17:19:47.226Z · upstream updated 2026-10-30T15:55:05.938Z

    Prioritization updated

    before

    []

    after

    [
  {
    "source": "CISA-ADP",
    "type": "SSVC",
    "role": "CISA Coordinator",
    "timestamp": "2026-10-30T15:20:58.656589Z",
    "decisions": [
      {
        "name": "Exploitation",
        "value": "none"
      },
      {
        "name": "Automatable",
        "value": "no"
      },
      {
        "name": "Technical Impact",
        "value": "partial"
      }
    ]
  }
]

Large field values are marked as truncated previews. Original source snapshots remain retained.

Showing up to 50 most recent observed changes.

References

7 sources
github.com/opnsense/core/security/advisories/GHSA-864r-q4j5-5mjq
vendor-advisoryVulnCheck
github.com/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55
patchVulnCheck
github.com/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834
patchVulnCheck
github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py
technical-descriptionVulnCheck
abraxaslabs.tech/research/opnsense-captive-lastseen-roam
third-party-advisoryVulnCheck
github.com/opnsense/core
productVulnCheck
View 1 more references
www.vulncheck.com/advisories/opnsense-26.1.6-through-26.7.7-captive-portal-session-takeover-via-forged-arp
third-party-advisoryVulnCheck