Description
HTTP/2 (2.4.20 through 2.4.39) very early pushes, for example configured with "H2PushResource", could lead to an overwrite of memory in the pushing request's pool, leading to crashes. The memory copied is that of the configured push link header values, not data supplied by the client.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | Apache HTTP Server | 2.4.20 to 2.4.39 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | apache2 | 2.4.41-1 | — |
| Debian 13 | apache2 | 2.4.41-1 | — |
| Debian 12 | apache2 | 2.4.41-1 | — |
| Debian 10 | apache2 | 2.4.38-3+deb10u1 | DSA-4509-1 |
| Debian 9 | apache2 | 2.4.25-3+deb9u8 | DSA-4509-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | apache2 | 2.4.29-1ubuntu4.10 | USN-4113-1 |
| Ubuntu 16.04 LTS | apache2 | 2.4.18-2ubuntu3.12 | USN-4113-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | httpd +6 | 2.4.37-30.module+el8.3.0+7001+0766b9e7 | RHSA-2020:4751 |
| RHEL 8 | mod_http2 | 1.15.7-2.module+el8.3.0+7670+8bf57d29 | RHSA-2020:4751 |
| RHEL 8 | mod_md | 1:2.0.8-8.module+el8.3.0+6814+67d1e611 | RHSA-2020:4751 |
| RHEL 8 | mod_ssl +1 | 1:2.4.37-30.module+el8.3.0+7001+0766b9e7 | RHSA-2020:4751 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Core Services 1 | jbcs-httpd24-apr +1 | 1.6.3-86.jbcs.el6 | RHSA-2020:1337 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-brotli +1 | 1.0.6-21.jbcs.el6 | RHSA-2020:1337 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-httpd +6 | 2.4.37-52.jbcs.el6 | RHSA-2020:1337 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_cluster-native | 1.3.12-41.Final_redhat_2.jbcs.el6 | RHSA-2020:1337 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_http2 | 1.11.3-22.jbcs.el6 | RHSA-2020:1337 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_ssl +1 | 1:2.4.37-52.jbcs.el6 | RHSA-2020:1337 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-openssl +4 | 1:1.1.1c-16.jbcs.el6 | RHSA-2020:1337 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | mod_md | 1:2.0.8-8.module_el8.5.0+2609+b30d9eec | ALSA-2020:4751 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | mod_md | 1:2.0.8-8.module+el8.4.0+553+7a69454b | RLSA-2020:4751 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | apache2 | 2.4.33-3.21.1 | SUSE-SU-2019:2237-1 |
| SLES 15 | apache2 | 2.4.33-3.21.1 | SUSE-SU-2019:2237-1 |
| SLES 12 SP4 | apache2 | 2.4.23-29.43.1 | SUSE-SU-2019:2329-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP4 | apache2 | 2.4.23-29.43.1 | SUSE-SU-2019:2329-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | apache2 | 2.4.49-1.1 | openSUSE-SU-2024:10623-1 |
| openSUSE Leap 15.1 | apache2 | 2.4.33-lp151.8.6.1 | openSUSE-SU-2019:2051-1 |
| openSUSE Leap 15.0 | apache2 | 2.4.33-lp151.8.6.1 | openSUSE-SU-2019:2051-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | apache2 | 2.4.41-r0 | — |
| Alpine v3.23 | apache2 | 2.4.41-r0 | — |
| Alpine v3.22 | apache2 | 2.4.41-r0 | — |
| Alpine v3.21 | apache2 | 2.4.41-r0 | — |
| Alpine v3.20 | apache2 | 2.4.41-r0 | — |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | apache2 | 2.4.41-r0 | — |
| Alpine v3.18 | apache2 | 2.4.41-r0 | — |
| Alpine v3.17 | apache2 | 2.4.41-r0 | — |
| Alpine v3.16 | apache2 | 2.4.41-r0 | — |
| Alpine v3.15 | apache2 | 2.4.41-r0 | — |
| Alpine v3.14 | apache2 | 2.4.41-r0 | — |
| Alpine v3.13 | apache2 | 2.4.41-r0 | — |
| Alpine v3.12 | apache2 | 2.4.41-r0 | — |
| Alpine v3.11 | apache2 | 2.4.41-r0 | — |
| Alpine v3.10 | apache2 | 2.4.41-r0 | — |
| Alpine v3.9 | apache2 | 2.4.41-r0 | — |
| Alpine v3.8 | apache2 | 2.4.41-r0 | — |
| Alpine v3.7 | apache2 | 2.4.41-r0 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | httpd +6 | 2.4.37-30.0.1.module+el8.3.0+7816+49791cfd | ELSA-2020-4751 |
| Oracle Linux 8 | mod_http2 | 1.15.7-2.module+el8.3.0+7816+49791cfd | ELSA-2020-4751 |
| Oracle Linux 8 | mod_md | 1:2.0.8-8.module+el8.3.0+7816+49791cfd | ELSA-2020-4751 |
| Oracle Linux 8 | mod_ssl +1 | 1:2.4.37-30.0.1.module+el8.3.0+7816+49791cfd | ELSA-2020-4751 |
Advisories 12
- ALSA-2020:4751 Moderate: httpd:2.4 security, bug fix, and enhancement update AlmaLinux Security Advisories · Nov 2, 2026
- RHSA-2020:4751 Red Hat Security Advisory: httpd:2.4 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2020:1337 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.37 SP2 security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- USN-4113-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-4509-1 apache2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2020:4751 Moderate: httpd:2.4 security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 5, 2026
- openSUSE-SU-2019:2051-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:2237-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:2329-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10623-1 apache2-2.4.49-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-1591 Juniper JUNOS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2024
- ELSA-2020-4751 Moderate: httpd:2.4 security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2020
References
- DSA-4509 vendor-advisory
- 20190826 [SECURITY] [DSA 4509-1] apache2 security update mailing-list
- USN-4113-1 vendor-advisory
- openSUSE-SU-2019:2051 vendor-advisory
- GLSA-201909-04 vendor-advisory
- [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/vulnerabilit mailing-list
- [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/vulnerabilit mailing-list
- https://www.oracle.com/security-alerts/cpuapr2020.html
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://security.netapp.com/advisory/ntap-20190905-0003/
- https://support.f5.com/csp/article/K84341091?utm_source=f5support&%3Butm_medium=RSS
- [httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073143 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/ mailing-list
- [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.ht mailing-list
- [httpd-cvs] 20210330 svn commit: r1073139 [12/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1888194 [12/13] - /httpd/site/trunk/content/security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [13/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [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/vulnerabiliti mailing-list