Apache HTTP Server: mod_http2 use-after-free / wild write via shared session->bbtmp re-entrancy
Priority MEDIUM 50CWE-416Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
Use After Free vulnerability in Apache HTTP Server's mod_http2 via shared session->bbtmp re-entrancy This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00594 48th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- 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 1 advisory
- 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: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat JBoss Core Services | Affected | No fix yet |
| Red Hat Hardened Images | Fixed | RHSA-2026:74858 |
Not affected: 5 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
Timeline
- 2026-10-02 Threatist record created from CVE-2026-57941
- 2026-10-03 Alias added: GHSA-w59m-qjff-crxx
- 2026-10-09 Affected versions changed · Red Hat
- 2026-10-09 CVSS score added · Red Hat
- 2026-10-10 Fix available: Red Hat Hardened Images · Red Hat
- 2026-10-10 Fix available: RHSA-2026:74858 · Red Hat
- 2026-10-12 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-2026-57941 · CVE Program
- CVE-2026-57941 · NVD
- FIRST EPSS
- GHSA-w59m-qjff-crxx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-57941 · 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