# CVE-2026-0637: Header Injection via Custom URL Configuration in Multiple WSO2 Products Allows Open Redirect and Log Forgery

Status: published. Published: 2026-08-06. Updated: 2026-11-04.

When a proxy server is configured with `customUrl.enabled`, the component accepts user-supplied input within forwarded HTTP headers without enforcing expected validation constraints. A malicious actor can manipulate these headers to influence the URL construction process, leading to an open redirect vulnerability. Additionally, unsanitized header values are written to application logs.

An attacker can exploit this to force redirection to arbitrary malicious domains, potentially enabling phishing attacks. Furthermore, they can inject forged entries into application logs, impacting the reliability of security logs and potentially hindering incident investigation.

## Remediation

- fix: Follow the instructions given on  https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4829/#solution https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4829/#solution (source: CNA: WSO2)

## Affected products and versions

- WSO2 / WSO2 API Manager: ≥ 0; < 3.2.0 (unknown, custom); ≥ 3.2.0; < 3.2.0.464 (affected, custom); ≥ 3.2.1; < 3.2.1.83 (affected, custom); ≥ 4.1.0; < 4.1.0.249 (affected, custom); ≥ 4.2.0; < 4.2.0.189 (affected, custom); ≥ 4.3.0; < 4.3.0.99 (affected, custom); ≥ 4.4.0; < 4.4.0.63 (affected, custom); ≥ 4.5.0; < 4.5.0.44 (affected, custom); ≥ 4.6.0; < 4.6.0.12 (affected, custom). Source: CNA: WSO2
- WSO2 / WSO2 API Control Plane: ≥ 0; < 4.5.0 (unknown, custom); ≥ 4.5.0; < 4.5.0.45 (affected, custom); ≥ 4.6.0; < 4.6.0.13 (affected, custom). Source: CNA: WSO2

## Severity and prioritization

- CVSS 3.1: 5.4 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N; source: CNA: WSO2

- CISA KEV: No listing in collected sources

- EPSS: 0.16% as of 2026-11-03; percentile 5.43%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-20, CWE-74

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4829/ (CNA: WSO2; vendor-advisory)

## Provenance

- CNA: WSO2: https://www.cve.org/CVERecord?id=CVE-2026-0637; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-0637; retrieved 2026-11-04; source updated Not reported

Revision: 1fd0fd9f1444298e747b68ac1013f926cf60eb13e416a5bf6e6634c9464843d0

Canonical: https://y2.dev/cve/CVE-2026-0637

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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