October CMS has Stored XSS in its Backend Editor Markup Classes
October is a Content Management System (CMS) and web platform. Versions prior to 3.7.14 and 4.1.10 contain a Stored Cross-Site Scripting (XSS) vulnerability in the Backend Editor Settings. The Markup Classes fields (used for paragraph styles, inline styles, table styles, etc.) did not sanitize input to valid CSS class name characters. Malicious values were rendered unsanitized in Froala editor dropdown menus, allowing JavaScript execution when any user opened a RichEditor. Exploitation could lead to privilege escalation if a superuser opens any RichEditor during routine content editing (e.g., editing a blog post), and requires authenticated backend access with editor settings permissions. This issue has been fixed in versions 3.7.14 and 4.1.10. To workaround this issue, restrict editor settings permissions to fully trusted administrators only
- Published
- Apr 14, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.3% · 15th percentile
- CWE
- CWE-79
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Report tools
Action score
20
Monitor
Low priority for now.
- CVSS
- 20 / 40 · 5.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 5.1
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| octobercms | october | cpe:2.3:a:octobercms:october |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- octobercms octoberup to 3.7.13 inclusive
- octobercms october4.0.0 and later · up to 4.1.9 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
octobercms october
- < 3.7.14, >= 4.0.0, < 4.1.10affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Packagist | october/system | from 4.0.0 · before 4.1.10 | 4.1.10 |
| Packagist | october/system | before 3.7.14 | 3.7.14 |
Same product
octobercms: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-32648Account Takeover in OctobercmsKEV93Now
- CVE-2017-1000119October CMS build 412 is vulnerable to PHP code execution in the file upload functionality resulting in site compromise and possibly other a46Plan
- CVE-2021-3311An issue was discovered in October through build 471.40Plan
- CVE-2017-1000196October CMS build 412 is vulnerable to PHP code execution in the asset manager functionality resulting in site compromise and possibly other40Plan
- CVE-2017-1000197October CMS build 412 is vulnerable to file path modification in asset move functionality resulting in creating creating malicious files on 39Monitor
- CVE-2017-1000194October CMS build 412 is vulnerable to Apache configuration modification via file upload functionality resulting in site compromise and poss39Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Packagist:october/system | 3.7.14 | Package registry (OSV) |
| Packagist:october/system | 4.1.10 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-249070 days apartOctober CMS has Stored XSS via Event Log Mail Preview20Monitor
- CVE-2026-251330 days apartOctober CMS has Stored XSS via SVG Filter Bypass19Monitor
- CVE-2025-6167494 days apartOctober CMS Vulnerable to Stored XSS via Editor and Branding Styles19Monitor
- CVE-2025-6167694 days apartOctober CMS Vulnerable to Stored XSS via Branding Styles19Monitor
- CVE-2026-279377 days apartOctober: Reflected XSS via DataTable Form Widget12Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- P
- Scope
- X
Weakness class (CWE)
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Root cause
User content is inserted into the page as HTML. The browser interprets the content as code rather than data.
The bug in code
The whole CWE-79 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
commentEl.innerHTML = comment.body;Fixed
commentEl.textContent = comment.body;Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.