CVE-2023-45802 [Medium] | Security Vulnerability in Http Server

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	1.46%	3.02%	+1.56%
2	2026-06-14	1.82%	1.46%	-0.36%
3	2026-06-12	—	1.82%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

1.46%

3.02%

+1.56%

2026-06-14

1.82%

1.46%

-0.36%

2026-06-12

—

1.82%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.9	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.2	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.9

3.1

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.2

3.6

[email protected]

OS Trackers for CVE-2023-45802

vendor	priority	summary	link
`alpine`	—	CVE-2023-45802: 1 source package rows (apache2); 7 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 0.	https://security.alpinelinux.org/vuln/CVE-2023-45802
`debian`	not yet assigned	CVE-2023-45802 not yet assigned priority: Debian including 1 source packages (apache2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2023-45802
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2023-45802
`suse`	high	CVE-2023-45802 severity important: SUSE including 299 source package names (4.3.13.9.57.60:apache2-2.4.51-150400.6.43.1, 4.3.13.9.57.60:apache2-prefork-2.4.51-150400.6.43.1, …), 513 product×package rows across 67 product lines (Container suse/manager/4.3/proxy-httpd, Image SLES15-SP3-SAPCAL-Azure, … (67 product lines)): Fixed 243, Known Affected 231, Will Not Fix 37, Known Not Affected 2.	https://www.suse.com/security/cve/CVE-2023-45802/
`ubuntu`	medium	CVE-2023-45802 medium priority: Ubuntu including 1 source packages (apache2), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 9, not-affected 2, needs-triage 1.	https://ubuntu.com/security/CVE-2023-45802

Affected software / configurations for CVE-2023-45802

Vendor	Product	Version	Raw CPE
apache	http_server	>= 2.4.17, < 2.4.58	cpe:2.3:a:apache:http_server::::::::
fedoraproject	fedora	37	cpe:2.3:o:fedoraproject:fedora:37:::::::*
fedoraproject	fedora	38	cpe:2.3:o:fedoraproject:fedora:38:::::::*
fedoraproject	fedora	39	cpe:2.3:o:fedoraproject:fedora:39:::::::*
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*

References for CVE-2023-45802

URL	Tags
https://httpd.apache.org/security/vulnerabilities_24.html	Vendor Advisory
https://lists.debian.org/debian-lts-announce/2024/05/msg00013.html	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/2MBEPPC36UBVOZZNAXFHKLFGSLCMN5LI/	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/BFQD3KUEMFBHPAPBGLWQC34L4OWL5HAZ/	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/WE2I52RHNNU42PX6NZ2RBUHSFFJ2LVZX/	Mailing List Third Party Advisory
https://security.netapp.com/advisory/ntap-20231027-0011/	Third Party Advisory

URL

CVE-2023-45802 | Apache HTTP Server: HTTP/2 stream memory not reclaimed right away on RST

Exploit prediction scoring system (EPSS) score for CVE-2023-45802

Common vulnerability scoring system (CVSS) metrics for CVE-2023-45802

Weakness enumeration for CVE-2023-45802

OS Trackers for CVE-2023-45802

Affected software / configurations for CVE-2023-45802

References for CVE-2023-45802