HTTP Server vulnerabilitiesAnd the versions its exploited flaws hit.
HTTP Server is made by Apache. We track 318 published vulnerabilities in it, across 267 versions. 5 of them are on the list of flaws known to be exploited, the newest added on 1 May 2025. If you run HTTP Server, check your version against the exploited flaws below and patch those first.
The most recent HTTP Server flaw added to the known-exploited list is CVE-2024-38475, on 1 May 2025. We keep watching the known-exploited list.
Which versions of HTTP Server do the exploited flaws hit?
Each exploited flaw lists the versions it affects, as published by the vendor. Find your version, then patch.
Which HTTP Server vulnerabilities are being exploited?
5 flaws are on the government list of vulnerabilities known to be exploited. These are the ones criminals are using now, so they go first, whatever their severity score says.
- 9.1Apache HTTP Server Improper Escaping of Output Vulnerability
Apache HTTP Server contains an improper escaping of output vulnerability in mod_rewrite that allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not...
- 9.0Apache HTTP Server-Side Request Forgery (SSRF)
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user.
- 7.8Apache HTTP Server Privilege Escalation Vulnerability
Apache HTTP Server, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute code with the...
- 7.5Apache HTTP Server Path Traversal Vulnerability
Apache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default �require all...
- 9.8Apache HTTP Server Path Traversal Vulnerability
Apache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default require all...
Which HTTP Server flaws are most likely to be used?
Ranked by the latest exploit-likelihood forecast: the chance each flaw is used in an attack in the next 30 days. A high severity score on its own doesn't tell you that. Flaws shared by many other makers' products are left out.
- >99%
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user.
- >99%
A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49.
- >99%
It was found that the fix for CVE-2021-41773 in Apache HTTP Server 2.4.50 was insufficient.
- >99%
Improper escaping of output in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not...
- 99%CVE-2011-3192High
The byterange filter in the Apache HTTP Server 1.3.x, 2.0.x through 2.0.64, and 2.2.x through 2.2.19 allows remote attackers to cause a denial of service (memory and CPU consumption) via a Range header that expresses...
- 97%CVE-2021-44790Critical
A carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser (r:parsebody() called from Lua scripts).
- 97%CVE-2006-3747High
Off-by-one error in the ldap scheme handling in the Rewrite module (mod_rewrite) in Apache 1.3 from 1.3.28, 2.0.46 and other versions before 2.0.59, and 2.2, when RewriteEngine is enabled, allows remote attackers to...
- 95%CVE-2006-3918Medium
http_protocol.c in (1) IBM HTTP Server 6.0 before 6.0.2.13 and 6.1 before 6.1.0.1, and (2) Apache HTTP Server 1.3 before 1.3.35, 2.0 before 2.0.58, and 2.2 before 2.2.2, does not sanitize the Expect header from an...
- 95%CVE-2002-0840Medium
Cross-site scripting (XSS) vulnerability in the default error page of Apache 2.0 before 2.0.43, and 1.3.x up to 1.3.26, when UseCanonicalName is "Off" and support for wildcard DNS is present, allows remote attackers...
- 95%CVE-2017-9798High
Apache httpd allows remote attackers to read secret data from process memory if the Limit directive can be set in a user's .htaccess file, or if httpd.conf has certain misconfigurations, aka Optionsbleed.
Running HTTP Server? We'll keep checking.
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1 flaw being exploited affects software Acme tracks
Apache HTTP Server contains an improper escaping of output vulnerability in mod_rewrite that allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code execution or source code disclosure.
- Matched to
- HTTP Server on Acme's software list
- What to do
- Patch first, then check for signs of use
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
We track 318 published vulnerabilities listed under the name HTTP Server, across 267 versions. The most recent HTTP Server flaw added to the known-exploited list is CVE-2024-38475, on 1 May 2025.
5 are on the list of flaws known to be exploited. The most recently added are CVE-2024-38475, CVE-2021-40438 and CVE-2019-0211.
Create a Precursor Intelligence account and track HTTP Server. We match it against every published flaw, give each one a risk score from 0 to 100 and keep watching, so you hear about new ones as soon as we know, by email, in the app or by webhook.