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TI-2026-51721 Aliases CVE-2026-73637GHSA-gr5c-77fq-wx32

Apache HTTP Server: mod_auth_digest DoS attack

Priority LOW 38CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Partial Red Hat: 4 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.

Summary

Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00466 40th percentileScored 2026-11-07
Fix Partial Red Hat: 4 advisoriesRed Hat: 4 fixed, 2 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

VendorProductAffected versionsFixed inStatusSource
ApacheApache HTTP Server2.4.0 – 2.4.68—No fix listedCNA
  • Apache HTTP Server VendorApache Affected 2.4.0 – 2.4.68 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*2.4.0 to before 2.4.69VulnerableApache
  • cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:* Versions 2.4.0 to before 2.4.69 Vulnerable ·Apache

Remediation

Red Hat 4 advisories

  • RHSA-2026:92616 Released 2026-10-29 · Red Hat rating Important
    httpd: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 Important
    httpd 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 Important
    httpd 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 Important
    Red 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 →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat JBoss Core ServicesAffectedNo fix yet: Fix deferred
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 ImagesFixed RHSA-2026:74858
Not affected: 1 product
  • Red Hat Enterprise Linux 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73637
  2. 2026-10-03 Alias added: GHSA-gr5c-77fq-wx32
  3. 2026-10-07 Affected versions changed · Red Hat
  4. 2026-10-23 Fix available: RHSA-2026:88229 · Red Hat
  5. 2026-10-23 Fix available: Red Hat Enterprise Linux AppStream (v. 9) · Red Hat
  6. 2026-10-26 Fix available: RHSA-2026:89860 · Red Hat
  7. 2026-10-26 Fix available: Red Hat Enterprise Linux AppStream (v. 10) · Red Hat
  8. 2026-10-30 Fix available: RHSA-2026:92616 · Red Hat
  9. 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream (v. 8) · Red Hat

References

Advisory 2

  • 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
See all 349 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences