Apache HTTP Server: mod_proxy_uwsgi Transfer-Encoding response smuggling
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 4 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') response smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi and a crafted uwsgi response with Transfer-Encoding. This issue affects Apache HTTP Server: from 2.4.30 through 2.4.68.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- 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 4 advisories
- RHSA-2026:92616 Released 2026-10-29 · Red Hat rating Importanthttpd:2.4 security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) httpd-2.4.37-65.module+el8.10.0+25092+6f3ea0dd.13.aarch64::httpd:2.4, httpd-2.4.37-65.module+el8.10.0+25092+6f3ea0dd.13.ppc64le::httpd:2.4, httpd-2.4.37-65.module+el8.10.0+25092+6f3ea0dd.13.s390x::httpd:2.4 +38
- RHSA-2026:89860 Released 2026-10-26 · Red Hat rating Importanthttpd security update
- Red Hat Enterprise Linux AppStream (v. 10) httpd-2.4.63-13.el10_2.8, httpd-core-2.4.63-13.el10_2.8, httpd-devel-2.4.63-13.el10_2.8 +8
- RHSA-2026:88229 Released 2026-10-22 · Red Hat rating Importanthttpd security update
- Red Hat Enterprise Linux AppStream (v. 9) httpd-2.4.62-13.el9_8.9, httpd-core-2.4.62-13.el9_8.9, httpd-devel-2.4.62-13.el9_8.9 +8
Show 1 more Red Hat advisories
- RHSA-2026:74858 Released 2026-10-02 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images httpd-2.4.69-1.hum1@aarch64, httpd-2.4.69-1.hum1@src, httpd-2.4.69-1.hum1@x86_64 +20
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat JBoss Core Services | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:89860 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:92616 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:88229 |
| Red Hat Hardened Images | Fixed | RHSA-2026:74858 |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-63718
- 2026-10-03 Alias added: GHSA-9fgx-g8xr-w8vf
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-23 Fix available: RHSA-2026:88229 · Red Hat
- 2026-10-23 Fix available: Red Hat Enterprise Linux AppStream (v. 9) · Red Hat
- 2026-10-26 Fix available: RHSA-2026:89860 · Red Hat
- 2026-10-26 Fix available: Red Hat Enterprise Linux AppStream (v. 10) · Red Hat
- 2026-10-30 Fix available: RHSA-2026:92616 · Red Hat
- 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream (v. 8) · 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-2026-63718 · CVE Program
- CVE-2026-63718 · NVD
- FIRST EPSS
- GHSA-9fgx-g8xr-w8vf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-63718 · 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