CVE-2026-120500: An Otter Wiki before 2.26.2 Stored XSS via Math Code Block
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.
Generated by VEDAS. Scores as of 2026-11-08 00:03 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
An Otter Wiki before 2.26.2 contains a stored cross-site scripting vulnerability in OtterwikiMdRenderer.block_code that allows attackers who can edit pages, including anonymous users under the default configuration, to inject arbitrary script. Attackers can place HTML inside a math fenced code block, which is rendered unescaped and executes for every viewer of the page.
Description quoted from the CVE record (assigned by VulnCheck, published 2026-11-02).
Weakness: 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 none, integrity none, availability none. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/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 5 references on Exploit Observer
Live scores
- EPSS
- 0.003
low predicted chance of attack - VEDAS
- 0.987
strong exploit evidence - On CISA KEV
- Not listed
- Detection rule
- Suricata
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| redimp otterwiki | from 2.0.0 before 2.26.2 | 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: 2.26.2.
Vendor guidance:
- https://github.com/redimp/otterwiki/commit/b2e91d20ed36c01ce140d18698f9abb90685d481 (patch)
- otterwiki v2.26.2 Release Notes (release-notes)
How to detect it
Suricata rules (network detection)
1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-120500 An Otter Wiki - Stored XSS via Math Code Fence Page Save Attempt. Add them to your Suricata rule set and reload.
Show the rules
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-120500 An Otter Wiki - Stored XSS via Math Code Fence Page Save Attempt"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/save"; nocase; fast_pattern; http.request_body; content:"content="; nocase; content:"math"; nocase; pcre:"/(on[a-z]{3,}\s*(=|%3[dD])|(<|%3[cC])(script|svg|img|iframe|body))/i"; classtype:web-application-attack; reference:cve,CVE-2026-120500; reference:url,https://www.exploit.observer/?keyword=CVE-2026-120500&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=otterwiki&match=exact; sid:1105000; rev:1;)
CVE-2026-120500.rules on GitHub
References
Vendor advisories and patches
- https://github.com/redimp/otterwiki/commit/b2e91d20ed36c01ce140d18698f9abb90685d481 (patch)
- otterwiki v2.26.2 Release Notes (release-notes)
Technical analysis and advisories
- VulnCheck Advisory: An Otter Wiki before 2.26.2 Stored XSS via Math Code Block (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.
Supporting partners
