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TI-2021-08374 Aliases CVE-2021-26690GHSA-f669-j28w-pjvg

mod_session NULL pointer dereference

Priority HIGH 69CWE-476Published · 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: 4 fixed, 4 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-476.

Summary

Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can cause a NULL pointer dereference and crash, leading to a possible Denial Of Service

Why it matters now

EPSS 0.65067 99th percentileScored 2026-11-07
Fix Partial Red Hat: 3 advisoriesRed Hat: 4 fixed, 4 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
ApacheApache HTTP Server2.4.46; 2.4.43; 2.4.41; 2.4.39; 2.4.38; 2.4.37; 2.4.35; 2.4.34; 2.4.33; 2.4.29; 2.4.28; 2.4.27; 2.4.26; 2.4.25; 2.4.23; 2.4.20; 2.4.18; 2.4.17; 2.4.16; 2.4.12; 2.4.10; 2.4.9; 2.4.7; 2.4.6; 2.4.4; 2.4.3; 2.4.2; 2.4.1; 2.4.0—No fix listedCNA
  • Apache HTTP Server VendorApache Affected 2.4.46; 2.4.43; 2.4.41; 2.4.39; 2.4.38; 2.4.37; 2.4.35; 2.4.34; 2.4.33; 2.4.29; 2.4.28; 2.4.27; 2.4.26; 2.4.25; 2.4.23; 2.4.20; 2.4.18; 2.4.17; 2.4.16; 2.4.12; 2.4.10; 2.4.9; 2.4.7; 2.4.6; 2.4.4; 2.4.3; 2.4.2; 2.4.1; 2.4.0 Fixed in — No fix listed CNA

CPE configurations NVD · 10

CPEVersionsRoleVendor
cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*2.4.0 – 2.4.46VulnerableApache
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*35VulnerableFedoraproject
cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*12.4.0.0VulnerableOracle
cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*17.1VulnerableOracle
cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*17.2VulnerableOracle
cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*17.3VulnerableOracle
cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*8.8VulnerableOracle
  • cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:* Versions 2.4.0 – 2.4.46 Vulnerable ·Apache
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
  • cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:* Versions 12.4.0.0 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:* Versions 17.1 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:* Versions 17.2 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:* Versions 17.3 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:* Versions 8.8 Vulnerable ·Oracle

Remediation

Red Hat 3 advisories

  • RHSA-2021:4614 Released 2021-11-10 · Red Hat rating Moderate
    Red Hat JBoss Core Services Apache HTTP Server 2.4.37 SP10 security update
    • Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-apr-1.6.3-107.jbcs.el7, jbcs-httpd24-apr-devel-1.6.3-107.jbcs.el7, jbcs-httpd24-apr-util-1.6.1-84.jbcs.el7 +36
    • Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-apr-1.6.3-107.el8jbcs, jbcs-httpd24-apr-devel-1.6.3-107.el8jbcs, jbcs-httpd24-apr-util-1.6.1-84.el8jbcs +36
  • RHSA-2021:4613 Released 2021-11-10 · Red Hat rating Moderate
    Red Hat JBoss Core Services Apache HTTP Server 2.4.37 SP10 security update
    • Red Hat JBoss Core Services
  • RHSA-2021:4257 Released 2021-11-09 · Red Hat rating Moderate
    httpd:2.4 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) httpd-2.4.37-41.module+el8.5.0+11772+c8e0c271.aarch64::httpd:2.4, httpd-2.4.37-41.module+el8.5.0+11772+c8e0c271.ppc64le::httpd:2.4, httpd-2.4.37-41.module+el8.5.0+11772+c8e0c271.s390x::httpd:2.4 +38

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Apache HTTP Server — GLSA-202107-38

    7 records Highest priority Priority HIGH 3 HIGH, 4 MEDIUM

    Other records, highest priority first

    • TI-2021-08375 Apache HTTP Server mod_session response handling heap overflowPriority HIGH 79
    • TI-2021-11716 NULL pointer dereference on specially crafted HTTP/2 requestPriority HIGH 71
    • TI-2020-17981 mod_auth_digest possible stack overflow by one nul bytePriority MEDIUM 64
    Show all 7 records → Advisory →
  • Advisory ·

    Apache HTTP Server — DSA-4937

    5 records Highest priority Priority HIGH 3 HIGH, 2 MEDIUM

    Other records, highest priority first

    • TI-2021-08375 Apache HTTP Server mod_session response handling heap overflowPriority HIGH 79
    • TI-2021-11716 NULL pointer dereference on specially crafted HTTP/2 requestPriority HIGH 71
    • TI-2020-17981 mod_auth_digest possible stack overflow by one nul bytePriority MEDIUM 64
    Show all 5 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat JBoss Enterprise Application Platform 6AffectedNo fix planned: Out of support scope
Red Hat JBoss Enterprise Web Server 2AffectedNo fix planned: Out of support scope
Red Hat Software CollectionsAffectedNo fix planned: Will not fix
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:4257
Red Hat JBoss Core ServicesFixed RHSA-2021:4613
Red Hat JBoss Core Services on RHEL 7 ServerFixed RHSA-2021:4614
Red Hat JBoss Core Services on RHEL 8Fixed RHSA-2021:4614
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-26690
  2. 2026-10-03 Alias added: GHSA-f669-j28w-pjvg

References

Advisory 10

Other 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