CVE-2025-9823: Reflected XSS in lead:addLeadTags - Quick Add
Noroxi assessment
Priority: Monitor (action score 19/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.31% (FIRST EPSS).
- 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.
- Fixed version: Mautic Mautic < 4.4.17, < 5.2.8, < 6.0.5.
Low priority for now. Upgrade to Mautic Mautic < 4.4.17, < 5.2.8, < 6.0.5 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
SummaryA Cross-Site Scripting (XSS) vulnerability allows an attacker to execute arbitrary JavaScript in the context of another user’s session. This occurs because user-supplied input is reflected back in the server’s response without proper sanitization or escaping, potentially enabling malicious actions such as session hijacking, credential theft, or unauthorized actions in the application. DetailsThe vulnerability resides in the “Tags” input field on the /s/ajax?action=lead:addLeadTags endpoint. Although the server applies sanitization before storing the data or returning it later, the payload is executed immediately in the victim’s browser upon reflection, allowing an attacker to run arbitrary JavaScript in the user’s session. ImpactA Reflected XSS attack can have a significant impact, allowing attackers to steal sensitive user data like cookies, redirect users to malicious websites, manipulate the web page content, and essentially take control of a user's session within an application by executing malicious JavaScript code within the victim's browser, even if the server-side code is secure; essentially enabling them to perform actions as if they were the logged-in user. References * Web Security Academy: Cross-site scripting https://portswigger.net/web-security/cross-site-scripting * Web Security Academy: Reflected cross-site scripting https://portswigger.net/web-security/cross-site-scripting/reflected
- Published
- Sep 3, 2025
- Updated
- Oct 19, 2026
- EPSS
- 0.3% · 24th percentile
- CWE
- CWE-79
Report tools
Action score
19
Monitor
Low priority for now.
- CVSS
- 19 / 40 · 4.8 / 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 · Mautic
- 4.8
- 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:A/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.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
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Limit the impact of XSS
This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.
Check security headersVersions reported by the vendor
Affected version ranges reported by the assigning authority (Mautic). Independent of NVD's CPE analysis and usually ahead of it.
Mautic Mautic
- >= 4.4.0 and later · before < 4.4.17affected · semver
- >= 5.0.0-alpha and later · before < 5.2.8affected · semver
- >= 6.0.0-alpha and later · before < 6.0.5affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Packagist | mautic/core | from 4.4.0 · before 4.4.17 | 4.4.17 |
| Packagist | mautic/core | from 5.0.0-alpha · before 5.2.8 | 5.2.8 |
| Packagist | mautic/core | from 6.0.0-alpha · before 6.0.5 | 6.0.5 |
Same product
mautic: all recordsOther highest-scoring records for the same primary product.
- CVE-2018-8092Mautic before 2.13.0 allows CSV injection.39Monitor
- CVE-2025-13828Mautic user without privileged access to the Marketplace can install and uninstall composer packages36Monitor
- CVE-2020-35129Mautic before 3.2.4 is affected by stored XSS.36Monitor
Published before and after this one in the same product
- ← EarlierCVE-2025-9821Sep 3, 2025 · SSRF via webhook function10Monitor
- ← EarlierCVE-2025-9822Sep 3, 2025 · Secret data extraction via elfinder22Monitor
- Later →CVE-2025-9824Sep 3, 2025 · User Enumeration via Response Timing23Monitor
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 |
|---|---|---|
| Mautic Mautic | < 4.4.17 | Vendor (CNA) |
| Mautic Mautic | < 5.2.8 | Vendor (CNA) |
| Mautic Mautic | < 6.0.5 | Vendor (CNA) |
| Packagist:mautic/core | 4.4.17 | Package registry (OSV) |
| Packagist:mautic/core | 5.2.8 | Package registry (OSV) |
| Packagist:mautic/core | 6.0.5 | 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.
No history yet (it accumulates with the daily EPSS job).
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.
- nmmorettereporter
- kuzmanyremediation reviewer
- patrykgruszkaremediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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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
- A
- 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:A/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
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Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.