CVE-2025-61638 | Sanitizer::validateAttributes data-XSS

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation MediaWiki, Wikimedia Foundation Parsoid. This vulnerability is associated with program files includes/parser/Sanitizer.Php, src/Core/Sanitizer.Php. This issue affects MediaWiki: from * before 1.39.14, 1.43.4, 1.44.1; Parsoid: from * before 0.16.6, 0.20.4, 0.21.1.

Published: 2026-02-03 Last update: 2026-03-16 Assigner: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc Source: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc

Conclusion & alert: CVE-2025-61638 is rated Low Risk (3.2/100): low exploitation likelihood (EPSS 0.02%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-61638

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-03 0.02%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-61638

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
0.0 4.0 NONE
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/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 Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:L)
Low privileges are required.
User interaction (UI:P)
A user has to participate (for example click/open/approve).
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:U)
Unreported: no public PoC, no reported exploitation, and no known simplification tools.
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
1.7 2.7 [email protected]

Weakness enumeration for CVE-2025-61638

OS Trackers for CVE-2025-61638

vendor priority summary link
debian not yet assigned CVE-2025-61638 not yet assigned priority: Debian including 1 source packages (mediawiki), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-61638
ubuntu medium CVE-2025-61638 medium priority: Ubuntu including 1 source packages (mediawiki), 7 status rows across 7 suites (bionic, focal, jammy, noble, plucky, questing, upstream): needs-triage 6, ignored 1. https://ubuntu.com/security/CVE-2025-61638

Affected software / configurations for CVE-2025-61638

Vendor Product Version Raw CPE
mediawiki mediawiki < 1.39.14 cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*
mediawiki mediawiki >= 1.39.15, < 1.43.4 cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*
mediawiki mediawiki >= 1.43.5, < 1.44.1 cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*
wikimedia parsoid < 0.16.6 cpe:2.3:a:wikimedia:parsoid:*:*:*:*:*:node.js:*:*
wikimedia parsoid > 0.16.6, < 0.20.4 cpe:2.3:a:wikimedia:parsoid:*:*:*:*:*:node.js:*:*
wikimedia parsoid > 0.20.4, < 0.21.1 cpe:2.3:a:wikimedia:parsoid:*:*:*:*:*:node.js:*:*

References for CVE-2025-61638

URL Tags
https://phabricator.wikimedia.org/T401099 Third Party Advisory
cvelogic Threat Intelligence