CVE-2026-116761: jtsternberg CMB2 advisory

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

The CMB2 plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘cmb43ex1_grp[0][txt] (wysiwyg field inside group, field id controlled by integrator config)’ parameter in all versions up to, and including, 2.13.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is only exploitable when a site integrator renders the plugin’s documented front-end form helper with a wysiwyg field inside a repeatable group on a publicly accessible page.

Description quoted from the CVE record (assigned by Wordfence, published 2026-10-28).

Weakness: CWE-79 Improper Neutralization of Input During Web Page Generation (‘Cross-site Scripting’)

How it can be exploited

Exploitable over the network with high attack complexity needing no privileges and no user interaction. Impact: confidentiality low, integrity low, availability none. CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: partial.

Public exploit evidence (Exploit Observer)

Also known as: GHSA-rfx8-wq2m-j436

VEDAS cluster: VEDAS:DRACODONKEY

Exploit Observer links 3 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (3)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Vulnerability databases and vendor advisories (3)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-rfx8-wq2m-j436
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-116761
Vulnerability database or vendor advisory: https://osv.dev/vulnerability/CVE-2026-116761

8 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.002
low predicted chance of attack
VEDAS: 0.988
strong exploit evidence
On CISA KEV: Not listed
Detection rule: Suricata

Who is affected

Product	Affected	Not affected
jtsternberg CMB2	up to and including 2.13.4	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

How to fix it

No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.

How to detect it

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-116761 WordPress CMB2 - Front-end wysiwyg Group Stored XSS. Add them to your Suricata rule set and reload.

Show the rules

suricata

# CVE-2026-116761 - CMB2 (WordPress) <= 2.13.4 stored XSS: a wysiwyg field inside a
# repeatable group rendered by the plugin's documented front-end form helper on a public
# page is insufficiently sanitized, letting an unauthenticated visitor store script. This
# matches a CMB2 front-end form submission (submit-cmb / object_id markers) whose body
# carries a script or HTML event-handler payload.
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-116761 WordPress CMB2 - Front-end wysiwyg Group Stored XSS"; flow:established,to_server; http.method; content:"POST"; http.request_body; content:"submit-cmb"; nocase; fast_pattern; content:"object_id"; nocase; pcre:"/(?:%3c|<)\s*(?:script|svg|img|iframe)[^>]*(?:on\w+\s*(?:%3d|=)|src\s*(?:%3d|=)|(?:%3e|>))|on(?:error|load|mouseover)\s*(?:%3d|=)/i"; classtype:web-application-attack; reference:cve,CVE-2026-116761; reference:url,https://www.exploit.observer/?keyword=CVE-2026-116761&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=wordpress&match=exact; sid:1098604; rev:1;)

CVE-2026-116761.rules on GitHub

References

Other references

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.