Apache HTTP Server: mod_proxy_html buffer overflow
Priority MEDIUM 41CWE-122Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 13 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-122 and the CVSS impact.
Summary
A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend. Users are recommended to upgrade to version 2.4.68, which fixes this issue.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01161 67th percentileScored 2026-11-07
Fix Partial Red Hat: 12 advisoriesRed Hat: 13 fixed, 1 without a fix
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 12 advisories
- RHSA-2026:92590 Released 2026-10-29 · Red Hat rating Importanthttpd security update
- Red Hat Enterprise Linux Server (v. 7 ELS) httpd-2.4.6-99.el7_9.8, mod_ssl-1:2.4.6-99.el7_9.8
- Red Hat Enterprise Linux Server Optional (v. 7 ELS) mod_proxy_html-1:2.4.6-99.el7_9.8
- RHSA-2026:67152 Released 2026-09-14 · Red Hat rating Importanthttpd security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) httpd-2.4.53-11.el9_2.15, httpd-core-2.4.53-11.el9_2.15, mod_ldap-2.4.53-11.el9_2.15 +2
- RHSA-2026:66323 Released 2026-09-10 · Red Hat rating Importanthttpd security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) httpd-2.4.57-11.el9_4.5, httpd-core-2.4.57-11.el9_4.5, mod_ldap-2.4.57-11.el9_4.5 +2
Show 9 more Red Hat advisories
- RHSA-2026:62165 Released 2026-09-01 · Red Hat rating Importanthttpd security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) httpd-2.4.62-4.el9_6.6, httpd-core-2.4.62-4.el9_6.6, httpd-devel-2.4.62-4.el9_6.6 +8
- RHSA-2026:56868 Released 2026-08-19 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.62 SP5 security update
- Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-httpd-2.4.62-16.el8jbcs, jbcs-httpd24-httpd-devel-2.4.62-16.el8jbcs, jbcs-httpd24-httpd-manual-2.4.62-16.el8jbcs +7
- RHSA-2026:56869 Released 2026-08-19 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.62 SP5 security update
- Red Hat JBoss Core Services 2.4.62.SP5
- RHSA-2026:53371 Released 2026-08-11 · Red Hat rating ImportantInsights proxy Container Image
- Red Hat Insights proxy 1.5 registry.redhat.io/insights-proxy/insights-proxy-container-rhel9
- RHSA-2026:47046 Released 2026-07-28 · Red Hat rating Importanthttpd security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) httpd-2.4.63-1.el10_0.4, httpd-core-2.4.63-1.el10_0.4, httpd-devel-2.4.63-1.el10_0.4 +8
- RHSA-2026:42828 Released 2026-07-21 · 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+24521+219dcfc5.9.aarch64::httpd:2.4, httpd-2.4.37-65.module+el8.10.0+24521+219dcfc5.9.ppc64le::httpd:2.4, httpd-2.4.37-65.module+el8.10.0+24521+219dcfc5.9.s390x::httpd:2.4 +38
- RHSA-2026:41906 Released 2026-07-20 · Red Hat rating Importanthttpd security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) httpd-2.4.62-13.el9_8.5, httpd-core-2.4.62-13.el9_8.5, httpd-devel-2.4.62-13.el9_8.5 +8
- RHSA-2026:34109 Released 2026-07-01 · Red Hat rating Importanthttpd security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) httpd-2.4.63-13.el10_2.4, httpd-core-2.4.63-13.el10_2.4, httpd-devel-2.4.63-13.el10_2.4 +8
- RHSA-2026:25042 Released 2026-06-10 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images httpd-2.4.68-1.hum1@aarch64, httpd-2.4.68-1.hum1@src, httpd-2.4.68-1.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 Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:34109 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:42828 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:41906 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:67152 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:66323 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:47046 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:62165 |
| Red Hat Enterprise Linux Server (v. 7 ELS) | Fixed | RHSA-2026:92590 |
| Red Hat Enterprise Linux Server Optional (v. 7 ELS) | Fixed | RHSA-2026:92590 |
| Red Hat Hardened Images | Fixed | RHSA-2026:25042 |
| Red Hat Insights proxy 1.5 | Fixed | RHSA-2026:53371 |
| Red Hat JBoss Core Services 2.4.62.SP5 | Fixed | RHSA-2026:56869 |
| Red Hat JBoss Core Services on RHEL 8 | Fixed | RHSA-2026:56868 |
Not affected: 6 products
- Red Hat Enterprise Linux AppStream E4S (v.9.2)
- Red Hat Enterprise Linux AppStream E4S (v.9.4)
- Red Hat Enterprise Linux Server (v. 7 ELS)
- Red Hat Enterprise Linux Server Optional (v. 7 ELS)
- Red Hat Hardened Images
- Red Hat JBoss Core Services on RHEL 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34355
- 2026-10-03 Alias added: GHSA-3qgf-pp84-379f
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-09 Fix available: RHSA-2026:56869 · Red Hat
- 2026-10-09 Fix available: Red Hat JBoss Core Services 2.4.62.SP5 · Red Hat
- 2026-10-16 Affected versions changed · Red Hat
- 2026-10-30 Fix available: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS) · Red Hat
- 2026-10-30 Fix available: RHSA-2026:92590 · 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-2026-34355 · CVE Program
- CVE-2026-34355 · NVD
- FIRST EPSS
- GHSA-3qgf-pp84-379f · GitHub Advisory Database · CC BY 4.0
- CVE-2026-34355 · 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