Apache HTTP Server: mod_ssl TLS upgrade attack
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-287.
Summary
In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade. Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Red Hat 15 advisories
- RHSA-2025:15698 Released 2025-09-11 · Red Hat rating Moderatehttpd:2.4 security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) httpd-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.src::httpd:2.4, httpd-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.x86_64::httpd:2.4, httpd-devel-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.x86_64::httpd:2.4 +11
- Red Hat Enterprise Linux AppStream E4S (v.8.6) httpd-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.aarch64::httpd:2.4, httpd-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.ppc64le::httpd:2.4, httpd-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.s390x::httpd:2.4 +38
- Red Hat Enterprise Linux AppStream TUS (v.8.6) httpd-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.src::httpd:2.4, httpd-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.x86_64::httpd:2.4, httpd-devel-2.4.37-47.module+el8.6.0+23463+5d5709c6.11.x86_64::httpd:2.4 +11
- RHSA-2025:15684 Released 2025-09-11 · Red Hat rating Moderatehttpd:2.4 security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) httpd-2.4.37-39.module+el8.4.0+23462+1fa78ba3.10.src::httpd:2.4, httpd-2.4.37-39.module+el8.4.0+23462+1fa78ba3.10.x86_64::httpd:2.4, httpd-devel-2.4.37-39.module+el8.4.0+23462+1fa78ba3.10.x86_64::httpd:2.4 +11
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) httpd-2.4.37-39.module+el8.4.0+23462+1fa78ba3.10.src::httpd:2.4, httpd-2.4.37-39.module+el8.4.0+23462+1fa78ba3.10.x86_64::httpd:2.4, httpd-devel-2.4.37-39.module+el8.4.0+23462+1fa78ba3.10.x86_64::httpd:2.4 +11
- RHSA-2025:15619 Released 2025-09-10 · Red Hat rating Moderatehttpd:2.4 security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) httpd-2.4.37-56.module+el8.8.0+23464+a2e0c444.10.ppc64le::httpd:2.4, httpd-2.4.37-56.module+el8.8.0+23464+a2e0c444.10.src::httpd:2.4, httpd-2.4.37-56.module+el8.8.0+23464+a2e0c444.10.x86_64::httpd:2.4 +20
Show 12 more Red Hat advisories
- RHSA-2025:15516 Released 2025-09-08 · Red Hat rating Moderatehttpd:2.4 security update
- Red Hat Enterprise Linux AppStream AUS (v. 8.2) httpd-2.4.37-21.module+el8.2.0+23461+1d03af5c.10.src::httpd:2.4, httpd-2.4.37-21.module+el8.2.0+23461+1d03af5c.10.x86_64::httpd:2.4, httpd-devel-2.4.37-21.module+el8.2.0+23461+1d03af5c.10.x86_64::httpd:2.4 +11
- RHSA-2025:15123 Released 2025-09-03 · Red Hat rating Moderatehttpd:2.4 security update
- Red Hat Enterprise Linux AppStream (v. 8) httpd-2.4.37-65.module+el8.10.0+23369+11a81384.5.aarch64::httpd:2.4, httpd-2.4.37-65.module+el8.10.0+23369+11a81384.5.ppc64le::httpd:2.4, httpd-2.4.37-65.module+el8.10.0+23369+11a81384.5.s390x::httpd:2.4 +38
- RHSA-2025:15095 Released 2025-09-02 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux AppStream (v. 10) httpd-2.4.63-1.el10_0.2, httpd-core-2.4.63-1.el10_0.2, httpd-devel-2.4.63-1.el10_0.2 +8
- RHSA-2025:15036 Released 2025-09-02 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION) httpd-2.2.15-71.el6_10.1, httpd-devel-2.2.15-71.el6_10.1, httpd-manual-2.2.15-71.el6_10.1 +2
- RHSA-2025:15023 Released 2025-09-02 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux AppStream (v. 9) httpd-2.4.62-4.el9_6.4, httpd-core-2.4.62-4.el9_6.4, httpd-devel-2.4.62-4.el9_6.4 +8
- RHSA-2025:14997 Released 2025-09-02 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux Server (v. 7 ELS) httpd-2.4.6-99.el7_9.6, httpd-devel-2.4.6-99.el7_9.6, httpd-manual-2.4.6-99.el7_9.6 +3
- Red Hat Enterprise Linux Server Optional (v. 7 ELS) mod_ldap-2.4.6-99.el7_9.6, mod_proxy_html-1:2.4.6-99.el7_9.6
- RHSA-2025:14998 Released 2025-09-02 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux Server AUS (v. 7.7) httpd-2.4.6-90.el7_7.6, httpd-devel-2.4.6-90.el7_7.6, httpd-manual-2.4.6-90.el7_7.6 +3
- Red Hat Enterprise Linux Server Optional AUS (v. 7.7) mod_ldap-2.4.6-90.el7_7.6, mod_proxy_html-1:2.4.6-90.el7_7.6
- RHSA-2025:14903 Released 2025-08-28 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux AppStream EUS (v.9.4) httpd-2.4.57-11.el9_4.3, httpd-core-2.4.57-11.el9_4.3, httpd-devel-2.4.57-11.el9_4.3 +8
- RHSA-2025:14902 Released 2025-08-28 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) httpd-2.4.53-11.el9_2.13, httpd-core-2.4.53-11.el9_2.13, httpd-devel-2.4.53-11.el9_2.13 +8
- RHSA-2025:14901 Released 2025-08-28 · Red Hat rating Moderatehttpd security update
- Red Hat Enterprise Linux AppStream E4S (v.9.0) httpd-2.4.51-7.el9_0.10, httpd-devel-2.4.51-7.el9_0.10, httpd-filesystem-2.4.51-7.el9_0.10 +7
- RHSA-2025:13681 Released 2025-08-14 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.62 SP1 security update
- Red Hat JBoss Core Services 2.4.62.SP1
- RHSA-2025:13680 Released 2025-08-14 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.62 SP1 security update
- Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-httpd-2.4.62-8.el7jbcs, jbcs-httpd24-httpd-devel-2.4.62-8.el7jbcs, jbcs-httpd24-httpd-manual-2.4.62-8.el7jbcs +12
- Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-httpd-2.4.62-8.el8jbcs, jbcs-httpd24-httpd-devel-2.4.62-8.el8jbcs, jbcs-httpd24-httpd-manual-2.4.62-8.el8jbcs +12
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2025:15095 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2025:15123 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:15023 |
| Red Hat Enterprise Linux AppStream AUS (v. 8.2) | Fixed | RHSA-2025:15516 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2025:15684 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2025:15698 |
| Red Hat Enterprise Linux AppStream E4S (v.8.6) | Fixed | RHSA-2025:15698 |
| Red Hat Enterprise Linux AppStream E4S (v.8.8) | Fixed | RHSA-2025:15619 |
| Red Hat Enterprise Linux AppStream E4S (v.9.0) | Fixed | RHSA-2025:14901 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2025:14902 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2025:14903 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) | Fixed | RHSA-2025:15684 |
| Red Hat Enterprise Linux AppStream TUS (v.8.6) | Fixed | RHSA-2025:15698 |
| Red Hat Enterprise Linux Server (v. 7 ELS) | Fixed | RHSA-2025:14997 |
| Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION) | Fixed | RHSA-2025:15036 |
| Red Hat Enterprise Linux Server AUS (v. 7.7) | Fixed | RHSA-2025:14998 |
| Red Hat Enterprise Linux Server Optional (v. 7 ELS) | Fixed | RHSA-2025:14997 |
| Red Hat Enterprise Linux Server Optional AUS (v. 7.7) | Fixed | RHSA-2025:14998 |
| Red Hat JBoss Core Services 2.4.62.SP1 | Fixed | RHSA-2025:13681 |
| Red Hat JBoss Core Services on RHEL 7 Server | Fixed | RHSA-2025:13680 |
| Red Hat JBoss Core Services on RHEL 8 | Fixed | RHSA-2025:13680 |
Timeline
- 2026-10-02 Threatist record created from CVE-2025-49812
- 2026-10-03 Alias added: GHSA-2mcx-3xj5-wg86
- 2026-10-09 Fix available: RHSA-2025:13681 · Red Hat
- 2026-10-18 Fix available: Red Hat JBoss Core Services 2.4.62.SP1 · 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-2025-49812 · CVE Program
- CVE-2025-49812 · NVD
- FIRST EPSS
- GHSA-2mcx-3xj5-wg86 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-49812 · Red Hat security data · CC BY 4.0
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