Medium Cross-site scripting

CVE-2025-10503 — Reflected Cross-Site Scripting via Authentication Endpoint in WSO2 Identity Server

The authentication endpoint accepts user-supplied input without enforcing expected validation constraints, leading to a lack of proper output encoding. This allows for the injection of malicious JavaScript payloads, enabling reflected cross-site scripting. An attacker can leverage this vulnerability to redirect the user's browser to a malicious website, modify the user interface of the web page, retrieve information from the browser, or cause other harmful actions. However, due to the protection of session-related cookies with the httpOnly flag, session hijacking is not possible.

Published Apr 29, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: WSO2

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.17%

ahead of 6% of scored CVEs · Oct 14, 2026

Affects

WSO2

Identity Server

CVSS base

6.1

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (WSO2 Identity Server).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
WSO2	Identity Server	≥ 7.1.0 and < 7.1.0.28	Vulnerable	NIST National Vulnerability Database
WSO2	Identity Server	≥ 7.1.0 and < 7.1.0.28	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
6.1	CVSS 3.1	Medium	2.8	2.7	ed10eef1-636d-4fbe-9993-6890dfa878f8 via NIST National Vulnerability Database
6.1	CVSS 3.1	Medium	—	—	WSO2 via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N (score shown at the top: ed10eef1-636d-4fbe-9993-6890dfa878f8)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-79 · Cross-site Scripting (XSS)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.17%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Monitor CSP violation reports and script payloads in reflected parameters.

web/proxy/WAF logsnetwork IDS/IPSapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · wso2/wso2 identity server
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 6.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Apr 29, 2026 · WSO2

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4
Vendor Advisory, vendor-advisory, NIST National Vulnerability Database

Elsewhere on this site

WSO2
every CVE for this vendor

Cross-site scripting
same class

CWE-79
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2024-8122 Potential brute force vulnerability due to non-expiring SMS OTPs 7d
Low CVE-2025-13166 Username Enumeration via SMS OTP Flow in WSO2 Identity Server Allows User Account Discovery Sep 15, 2026
Medium CVE-2026-0637 Insertion of Sensitive Information into Log File in WSO2 Api Control Plane Aug 6, 2026
Critical CVE-2025-15039 The Conditional Authentication (Adaptive Authentication) script does not correctly… Aug 6, 2026
Low CVE-2025-13736 Observable Discrepancy in WSO2 Api Manager Aug 6, 2026
Medium CVE-2025-13909 Improper Input Validation in WSO2 Identity Server Aug 6, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-10503 is "Reflected Cross-Site Scripting via Authentication Endpoint in WSO2 Identity Server", rated Medium. It affects Identity Server (WSO2); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.1 describes technical severity. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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