VulnerabilityPublished 10 Jan 2026Updated 12 Jan 2026

CVE-2025-61676: octobercms october · Cross-site Scripting

Affects octobercms octoberSource CVE Database V5

Not known to be exploited · CVSS 6.1 Medium : upgrade to 4.0.12 or 3.7.13 when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

6.1Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.0.12, 3.7.13

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade october to 4.0.12 or 3.7.13; octobercms/october to 3.7.13.

Affected software

Product	Affected	Fixed in
octobercmsoctober	Affected >=4.0.0 <4.0.12	Fixed in 4.0.12
octobercmsoctober	Affected <3.7.13	Fixed in 3.7.13
GitHuboctobercms/october`pkg:github/octobercms/october`Other threats	Affected <3.7.13	Fixed in 3.7.13

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Immediately upgrade October CMS installations to version 3.7.13 or 4.0.12 or later to apply the official patch addressing this vulnerability.
Review and restrict backend user permissions, ensuring only trusted users have the 'Customize Backend Styles' permission.
Implement strict access controls and multi-factor authentication (MFA) for all backend users to reduce the risk of account compromise.
Conduct regular audits of backend user activities and permissions to detect any unauthorized changes or suspicious behavior.
Employ Content Security Policy (CSP) headers to limit the impact of potential XSS attacks by restricting script execution sources.
Monitor logs for unusual backend activity or attempts to inject malicious styles or scripts.
Educate backend users about the risks of XSS and the importance of cautious input handling.
If patching is temporarily not possible, consider disabling or limiting access to the Branding & Appearance settings for non-essential users as a temporary workaround.

Description

October is a Content Management System (CMS) and web platform. Prior to versions 3.7.13 and 4.0.12, a cross-site scripting (XSS) vulnerabilities was identified in October CMS backend configuration forms. A user with the Customize Backend Styles permission could inject malicious HTML/JS into the stylesheet input at Styles from Branding & Appearance settings. A specially crafted input could break out of the intended <style> context, allowing arbitrary script execution across backend pages for all users. This issue has been patched in versions 3.7.13 and 4.0.12.

Impact

For European organizations using October CMS versions prior to 3.7.13 or 4.0.12, this vulnerability could lead to significant security risks within their backend management interfaces. Successful exploitation allows attackers with specific backend permissions to execute arbitrary JavaScript, potentially leading to session hijacking, unauthorized actions, or further compromise of administrative accounts. This could result in data breaches, defacement, or disruption of web services. Since the vulnerability requires authenticated access with the 'Customize Backend Styles' permission, insider threats or compromised accounts pose a particular risk. The impact is heightened for organizations with multiple backend users or those that grant broad permissions. Given the widespread use of October CMS in Europe for various web applications, especially in small to medium enterprises and public sector websites, the vulnerability could affect critical infrastructure and sensitive data. However, the lack of known exploits in the wild and the requirement for elevated permissions somewhat limit the immediate risk. Nonetheless, unpatched systems remain vulnerable to targeted attacks or insider misuse.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/octobercms/october/security/advisories/GHSA-wvpq-h33f-8rp6 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Jan 2026, 07:52 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

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