Use after free in Apache HTTP Server
Priority MEDIUM 45CWE-416Published · 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
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.
Summary
When under stress, closing many connections, the HTTP/2 handling code in Apache httpd 2.4.26 would sometimes access memory after it has been freed, resulting in potentially erratic behaviour.
Why it matters now
EPSS 0.09507 95th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
Not affected: 10 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat JBoss Core Services
- Red Hat JBoss Enterprise Application Platform 5
- Red Hat JBoss Enterprise Application Platform 6
- Red Hat JBoss Enterprise Web Server 1
- Red Hat JBoss Enterprise Web Server 2
- Red Hat JBoss Web Server 3
- Red Hat Software Collections
Timeline
- 2026-10-02 Threatist record created from CVE-2017-9789
- 2026-10-03 Alias added: GHSA-p7q7-pxmj-xgvj
References
Other 18
- [announce] 20170713 CVE-2017-9789: Apache httpd 2.4 Read after free in mod_http2
- https://support.apple.com/HT208221
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03908en_us
- https://security.netapp.com/advisory/ntap-20170911-0002/
- [httpd-cvs] 20190815 svn commit: r1048743 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20190815 svn commit: r1048742 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20200401 svn commit: r1058586 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20200401 svn commit: r1058587 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/
- [httpd-cvs] 20210330 svn commit: r1073140 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20210330 svn commit: r1073139 [11/13] - in /websites/staging/httpd/trunk/content: ./ security/json/
- [httpd-cvs] 20210330 svn commit: r1888194 [11/13] - /httpd/site/trunk/content/security/json/
- [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/
- [httpd-cvs] 20210330 svn commit: r1073149 [11/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/
- [httpd-cvs] 20210330 svn commit: r1073146 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities-httpd.xml security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20210603 svn commit: r1075360 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20210606 svn commit: r1075467 [2/2] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20210606 svn commit: r1075470 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2020-13938.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
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-2017-9789 · CVE Program
- CVE-2017-9789 · NVD
- FIRST EPSS
- GHSA-p7q7-pxmj-xgvj · GitHub Advisory Database · CC BY 4.0
- CVE-2017-9789 · 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