# CVE-2026-93903: CVE-2026-93903

Status: published. Published: 2026-09-30. Updated: 2026-11-05.

LiteSpeed Web Server (LSWS) before 6.3.7 build 1 mishandles internal redirect URL validation in a certain "corner case" of %252e%252e double decoding, letting a low-privileged tenant execute code in the context of a different account.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- litespeedtech / LiteSpeed Web Server: ≥ 0; < 6.3.7 build 1 (affected, custom). Source: CNA: mitre

## Severity and prioritization

- CVSS 4.0: 9.4 (critical); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H; source: CNA: mitre

- CISA KEV: No listing in collected sources

- EPSS: 0.28% as of 2026-11-04; percentile 20.98%

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

- Weaknesses: CWE-174

## Exploit evidence

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

## References

- https://lnkd.in/p/d2HZDcUC (CNA: mitre; third-party-advisory)

- https://www.litespeedtech.com/products/litespeed-web-server/release-log (CNA: mitre)

- https://docs.litespeedtech.com/lsws/changelog/#v6-3-7-build-1 (CNA: mitre)

- https://github.com/Tautvydas-Aleliunas/CVE-2026-93903 (CNA: mitre)

## Provenance

- CNA: mitre: https://www.cve.org/CVERecord?id=CVE-2026-93903; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-93903; retrieved 2026-11-05; source updated Not reported

Revision: 7fa989b022a59c2632b021c8f64226e8c0fd8dc8069ae08c112e0cd34b5ecf72

Canonical: https://y2.dev/cve/CVE-2026-93903

## 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.

Collected public records only. Check source status for coverage and freshness.