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Fencer Intel
high 7.1

CVE-2026-71490 json

OPNsense: Direct comma-separated user privileges bypass OPNsense MVC read-only write protection

published 4mo ago modified 27d ago also EUVD-2026-102140 , GHSA-p9pr-782r-w2xw

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository opnsense/core. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.11, OPNsense\Core\ACL::hasPrivilege() appends a directly assigned comma-separated <priv> value as one string and then uses an exact comparison when checking user-config-readonly. A user directly assigned both a component write privilege and user-config-readonly can therefore be treated as lacking the read-only restriction, and MVC APIs protected by throwReadOnly() can persist configuration changes for that component. Group privileges are not affected by the same parser flaw because the group path already splits comma-separated values. This issue is fixed in version 26.1.11.

Patch / fix

  • opnsense opnsense 26.1.11

Is CVE-2026-71490 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
27d ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/opnsense/core/security/advisories/GHSA-p9pr-782r-w2xw referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

Affected products

  • opnsense core

Classification

Weakness

References

Sources

Fencer Intel 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.

The maintainers of opnsense/core published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.