CVE-2026-56785: FlatPress 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

FlatPress contains a stored cross-site scripting vulnerability in comment and contact forms where name, URL, and email fields are rendered without proper output encoding in Smarty templates. Attackers can inject arbitrary HTML and JavaScript through these fields to execute malicious scripts in browsers of viewers including administrators, or bypass URL scheme validation to inject javascript: or data: URIs.

Description quoted from the CVE record (assigned by VulnCheck, published 2026-06-23).

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

How it can be exploited

Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and a user must take an action. Impact: confidentiality high, integrity low, availability none. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N

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

Public exploit evidence (Exploit Observer)

Exploit Observer found 3 code repositories naming this CVE.

Code repositories that name a CVE are often scanners, copies or fakes, and some are malware. Read the code before running anything.

See all 6 references on Exploit Observer

Live scores

EPSS: 0.004
low predicted chance of attack
VEDAS: 0.986
strong exploit evidence
On CISA KEV: Not listed
Detection rule: Suricata

Who is affected

Product	Affected	Not affected
FlatPress	before 10be83c	Not stated

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

How to fix it

Fixed versions stated in the CVE record: 10be83c.

Vendor guidance:

https://github.com/flatpressblog/flatpress/commit/10be83cbaac5ce0e51250b9d57de7f257b8f34f8 (patch)
https://github.com/dilipk5/flatpressd-cms-sxss (vendor-advisory)

How to detect it

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-56785 FlatPress - Stored XSS via Comment Fields. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-56785 FlatPress - Stored XSS via Comment Fields"; flow:established,to_server; http.method; content:"POST"; http.request_body; content:"csrf_token="; nocase; fast_pattern; content:"content="; nocase; pcre:"/(?:^|&)(?:name|url|email)=[^&]*(?:(?:%3c|<)\s*(?:script|img|svg|iframe|body|a\b)|on(?:error|load|click|mouseover)\s*(?:%3d|=)|(?:java|vb)script(?:%3a|\x3a)|data(?:%3a|\x3a)[^&]*base64)/i"; classtype:web-application-attack; reference:cve,CVE-2026-56785; reference:url,https://www.exploit.observer/?keyword=CVE-2026-56785&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=flatpress&match=exact; sid:1079403; rev:1;)

CVE-2026-56785.rules on GitHub

References

Vendor advisories and patches

https://github.com/flatpressblog/flatpress/commit/10be83cbaac5ce0e51250b9d57de7f257b8f34f8 (patch)
https://github.com/dilipk5/flatpressd-cms-sxss (vendor-advisory)

Technical analysis and advisories

https://www.vulncheck.com/advisories/flatpress-stored-cross-site-scripting-via-unescaped-comment-and-contact-form-fields (third-party-advisory)

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.