Description
When a HTTP/2 stream was reset (RST frame) by a client, there was a time window were the request's memory resources were not reclaimed immediately. Instead, de-allocation was deferred to connection close. A client could send new requests and resets, keeping the connection busy and open and causing the memory footprint to keep on growing. On connection close, all resources were reclaimed, but the process might run out of memory before that.
This was found by the reporter during testing of CVE-2023-44487 (HTTP/2 Rapid Reset Exploit) with their own test client. During "normal" HTTP/2 use, the probability to hit this bug is very low. The kept memory would not become noticeable before the connection closes or times out.
Users are recommended to upgrade to version 2.4.58, which fixes the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.17 – ≤ 2.4.57 | — |
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 | 2.4.58-1 | — |
| Debian 13 | apache2 | 2.4.58-1 | — |
| Debian 12 | apache2 | 2.4.59-1~deb12u1 | DSA-5662-1 |
| Debian 11 | apache2 | 2.4.59-1~deb11u1 | DSA-5662-1 |
| Debian 10 | apache2 | 2.4.59-1~deb10u1 | DLA-3818-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | apache2 | 2.4.58-1ubuntu1 | — |
| Ubuntu 22.04 LTS | apache2 | 2.4.52-1ubuntu4.7 | USN-6506-1 |
| Ubuntu 20.04 LTS | apache2 | 2.4.41-4ubuntu3.15 | USN-6506-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | apache2 | 2.4.41-4ubuntu3.23+esm3 | USN-8338-1 |
| Ubuntu Pro 18.04 LTS | apache2 | 2.4.29-1ubuntu4.27+esm7 | USN-8338-1 |
| Ubuntu Pro 16.04 LTS | apache2 | 2.4.18-2ubuntu3.17+esm17 | USN-8338-1 |
| Ubuntu Pro 14.04 LTS | apache2 | 2.4.7-1ubuntu4.22+esm12 | USN-8338-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | mod_http2 | 2.0.26-1.el9 | RHSA-2024:2368 |
| RHEL 8 | httpd +6 | 2.4.37-64.module+el8.10.0+21332+dfb1b40e | RHSA-2024:3121 |
| RHEL 8 | mod_http2 | 1.15.7-10.module+el8.10.0+21653+eaff63f0 | RHSA-2024:3121 |
| RHEL 8 | mod_md | 1:2.0.8-8.module+el8.9.0+19080+567b90f8 | RHSA-2024:3121 |
| RHEL 8 | mod_ssl +1 | 1:2.4.37-64.module+el8.10.0+21332+dfb1b40e | RHSA-2024:3121 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.8 EUS | httpd +6 | 2.4.37-56.module+el8.8.0+19808+379766d6.7 | RHSA-2024:2891 |
| RHEL 8.8 EUS | mod_http2 | 1.15.7-8.module+el8.8.0+21773+20528f83.5 | RHSA-2024:2891 |
| RHEL 8.8 EUS | mod_md | 1:2.0.8-8.module+el8.3.0+6814+67d1e611 | RHSA-2024:2891 |
| RHEL 8.8 EUS | mod_ssl +1 | 1:2.4.37-56.module+el8.8.0+19808+379766d6.7 | RHSA-2024:2891 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-curl +2 | 8.4.0-2.el7jbcs | RHSA-2023:7625 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_http2 | 1.15.19-32.el7jbcs | RHSA-2023:7625 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_jk +1 | 1.2.49-1.redhat_1.el7jbcs | RHSA-2023:7625 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-openssl +4 | 1:1.1.1k-16.el7jbcs | RHSA-2023:7625 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | mod_http2 | 2.0.26-1.el9 | ALSA-2024:2368 |
| AlmaLinux 8 | httpd +6 | 2.4.37-64.module_el8.10.0+3761+75f8c656 | ALSA-2024:3121 |
| AlmaLinux 8 | mod_http2 | 1.15.7-10.module_el8.10.0+3832+564e7653 | ALSA-2024:3121 |
| AlmaLinux 8 | mod_md | 1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa | ALSA-2024:3121 |
| AlmaLinux 8 | mod_ssl +1 | 1:2.4.37-64.module_el8.10.0+3761+75f8c656 | ALSA-2024:3121 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | httpd | 2.4.37-64.module+el8.10.0+1717+030a9fed | RLSA-2024:3121 |
| Rocky Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+1775+6b057638 | RLSA-2024:3121 |
| Rocky Linux 8 | mod_md | 1:2.0.8-8.module+el8.9.0+1370+89cc8ad5 | RLSA-2024:3121 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
| SLES 15 SP5 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2026:2686-1, SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
| SLES 15 SP4 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2026:2686-1, SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
| SLES 15 SP3 | apache2 | 2.4.51-150200.3.76.1 | SUSE-SU-2024:3962-1 |
| SLES 15 SP2 | apache2 | 2.4.51-150200.3.76.1 | SUSE-SU-2024:3962-1 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | apache2 +1 | 2.4.51-35.66.1 | SUSE-SU-2024:3949-1 |
| SLES for SAP 15 SP5 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
| SLES for SAP 15 SP4 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2026:2686-1, SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
| SLES for SAP 15 SP3 | apache2 | 2.4.51-150200.3.76.1 | SUSE-SU-2024:3962-1 |
| SLES for SAP 15 SP2 | apache2 | 2.4.51-150200.3.76.1 | SUSE-SU-2024:3962-1 |
| SLE HPC 15 SP5 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
| SLE HPC 15 SP4 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2026:2686-1, SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
| SLE HPC 15 SP3 | apache2 | 2.4.51-150200.3.76.1 | SUSE-SU-2024:3962-1 |
| SLE HPC 15 SP2 | apache2 | 2.4.51-150200.3.76.1 | SUSE-SU-2024:3962-1 |
| SUSE Manager Server 4.3 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
| SUSE Manager Proxy 4.3 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
| SUSE Enterprise Storage 7.1 | apache2 | 2.4.51-150200.3.76.1 | SUSE-SU-2024:3962-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | apache2 | 2.4.58-1.1 | openSUSE-SU-2024:13350-1 |
| openSUSE Leap 15.5 | apache2 | 2.4.51-150400.6.40.1 | SUSE-SU-2024:3999-1, SUSE-SU-2024:3961-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | apache2 | 2.4.58-r0 | — |
| Alpine v3.23 | apache2 | 2.4.58-r0 | — |
| Alpine v3.22 | apache2 | 2.4.58-r0 | — |
| Alpine v3.21 | apache2 | 2.4.58-r0 | — |
| Alpine v3.20 | apache2 | 2.4.58-r0 | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | apache2 | 2.4.58-r0 | — |
| Alpine v3.18 | apache2 | 2.4.58-r0 | — |
| Alpine v3.17 | apache2 | 2.4.58-r0 | — |
| Alpine v3.16 | apache2 | 2.4.58-r0 | — |
| Alpine v3.15 | apache2 | 2.4.58-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | httpd +8 | 2.4.58-1.amzn2023 | ALAS2023-2023-433 |
| Amazon Linux 2023 | mod_ssl +1 | 1:2.4.58-1.amzn2023 | ALAS2023-2023-433 |
| Amazon Linux 2 | httpd +7 | 2.4.58-1.amzn2 | ALAS2-2023-2322 |
| Amazon Linux 2 | mod_ssl +1 | 1:2.4.58-1.amzn2 | ALAS2-2023-2322 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | mod_http2 | 2.0.29-3 | — |
| Azure Linux 2 (CBL-Mariner) | httpd | 2.4.58-1 | — |
| Azure Linux 2 (CBL-Mariner) | mod_http2 | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | mod_http2 | 2.0.26-1.el9 | ELSA-2024-2368 |
| Oracle Linux 8 | httpd +6 | 2.4.37-64.module+el8.10.0+90271+3bc76a16 | ELSA-2024-3121 |
| Oracle Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+90327+96b8ea28 | ELSA-2024-3121 |
| Oracle Linux 8 | mod_md | 1:2.0.8-8.module+el8.9.0+90011+2f9c6a23 | ELSA-2024-3121 |
| Oracle Linux 8 | mod_ssl +1 | 1:2.4.37-64.module+el8.10.0+90271+3bc76a16 | ELSA-2024-3121 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
MehranTurk/CVE-2023-45802 ★ 1 · Apr 19, 2026
CVE-2023-45802 - Apache HTTP/2 Memory Exhaustion DoS Apache versions: 2.4.17 through 2.4.57 Target: Apache/2.4.52 (Ubuntu) - VULNERABLE MehranTurk (M.T) WARNING: For authorized testing in LAB environ…
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 28
- ALSA-2024:2368 Moderate: mod_http2 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2024:3121 Moderate: httpd:2.4 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2023:7625 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.57 SP2 security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2024:2891 Red Hat Security Advisory: httpd:2.4 security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RHSA-2024:3121 Red Hat Security Advisory: httpd:2.4 security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2024:2368 Red Hat Security Advisory: mod_http2 security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- WID-SEC-2023-2712 Apache HTTP Server: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Sep 10, 2026
- SUSE-SU-2026:2686-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 1, 2026
- WID-SEC-2023-2917 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 30, 2026
- USN-8338-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · May 29, 2026
- USN-6506-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5662-1 apache2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3818-1 apache2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2024:3121 Moderate: httpd:2.4 security update Rocky Linux Security Advisories · Feb 5, 2026
- openSUSE-SU-2024:13350-1 apache2-2.4.58-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3949-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3962-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3999-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3961-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- ICSA-25-133-01 Hitachi Energy Service Suite CISA ICS & IT advisories · Feb 25, 2025
- WID-SEC-2024-0769 IBM Rational Build Forge: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 7, 2024
- NCSC-2024-0332 Kwetsbaarheden verholpen in Siemens producten NCSC-NL (Netherlands) · Aug 13, 2024
- SSA-784301 SSA-784301: Multiple Vulnerabilities in SINEC NMS Before V3.0 Siemens ProductCERT · Aug 13, 2024
- ICSA-24-228-06 Siemens SINEC NMS CISA ICS & IT advisories · Aug 13, 2024
- ELSA-2024-3121 Moderate: httpd:2.4 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 24, 2024
- ELSA-2024-2368 Moderate: mod_http2 security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · May 2, 2024
- ALAS2023-2023-433 Important: httpd security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Nov 14, 2023
- ALAS2-2023-2322 Important: httpd security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Nov 1, 2023
References
- https://httpd.apache.org/security/vulnerabilities_24.html vendor-advisory