Apache HTTP Server: NTLM Leakage on Windows through UNC SSRF
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-918 and the CVSS impact.
Summary
Server-Side Request Forgery (SSRF) vulnerability in Apache HTTP Server on Windows with AllowEncodedSlashes On and MergeSlashes Off allows to potentially leak NTLM hashes to a malicious server via SSRF and malicious requests or content Users are recommended to upgrade to version 2.4.66, which fixes the issue.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Red Hat 1 advisory
- RHSA-2026:5156 Released 2026-03-19 · Red Hat rating ImportantRed Hat Hardened Images RPM Release
- Red Hat Hardened Images httpd-2.4.66-6.hum1@aarch64, httpd-2.4.66-6.hum1@src, httpd-2.4.66-6.hum1@x86_64 +10
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Hardened Images | Fixed | RHSA-2026:5156 |
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat Hardened Images
- Red Hat JBoss Core Services
Timeline
- 2026-10-02 Threatist record created from CVE-2025-59775
- 2026-10-03 Alias added: GHSA-7w72-74p3-5cfq
- 2026-11-02 Affected versions changed · Red Hat
References
More Apache Http Server vulnerabilities
- TI-2021-18535 Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) KEVCVSS 3.1CRITICAL 9.8
- TI-2021-18417 Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49 KEVCVSS 3.1CRITICAL 9.8
- TI-2024-25716 Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path. KEVCVSS 3.1CRITICAL 9.1
- TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
- TI-2019-00184 Use after free in Apache HTTP Server KEVCVSS 3.1HIGH 7.8
- TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
Sources
- CVE-2025-59775 · CVE Program
- CVE-2025-59775 · NVD
- FIRST EPSS
- GHSA-7w72-74p3-5cfq · GitHub Advisory Database · CC BY 4.0
- CVE-2025-59775 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences