CVE-2019-0211

CVE-2019-0211 affects Apache HTTP Server 2.4.17–2.4.38 when using MPM event, worker, or prefork. The issue arises from code executing in less-privileged child processes/threads (including in-process scripting interpreters) that could be exploited to run arbitrary code with the privileges of the p...

CVE-2017-7668

The Apache httpd server is vulnerable to a buffer over-read in the ap_find_token() function. This issue originated from HTTP strict parsing changes introduced in versions 2.2.32 and 2.4.24 . A remote attacker can exploit this by sending a maliciously crafted sequence of request headers, potential...

CVE-2019-9517

CVE-2019-9517 describes an attack against some HTTP/2 implementations where unconstrained internal data buffering can cause a denial of service. The vulnerability arises when an attacker floods a connection with a large number of requests for a large response object while manipulating HTTP/2 flow...

CVE-2023-38709

Apache HTTP Server (versions through 2.4.58 ) is vulnerable to HTTP response splitting due to faulty input validation in the core. This flaw allows malicious or exploitable backend/content generators to insert unsanitized headers, such as Content-Type or Content-Encoding , into the response. Prac...

CVE-2011-3192

CVE-2011-3192 is a DoS flaw in the Apache HTTP Server related to how Range headers are processed. In affected releases of httpd (1.3.x, 2.0.x up to 2.0.64, and 2.2.x up to 2.2.19), a remote attacker can trigger excessive memory and CPU usage by sending a Range header with multiple overlapping ran...

CVE-2017-9798

The Apache HTTP Server is vulnerable to a use-after-free issue, commonly referred to as Optionsbleed , affecting versions through 2.2.34 and 2.4.27 . A remote, unauthenticated attacker can send a specially crafted OPTIONS HTTP request to read secret data from the process memory. This vulnerabilit...

CVE-2018-17199

In Apache HTTP Server 2.4.x up to 2.4.37, the vulnerability CVE-2018-17199 is caused by mod_session_cookie: the session expiry time is checked before decoding the session, so expiry is ignored for mod_session_cookie sessions. This means session expiry may not be enforced for affected sessions. Th...

CVE-2019-0217

This CVE affects Apache HTTP Server 2.4.x up to 2.4.38, where a race condition in mod_auth_digest could allow an authenticated user to act as another user and bypass access control. The issue is tied to running in threaded MPMs; the underlying cause is a race condition in authentication handling....

CVE-2020-9490

CVE-2020-9490 affects Apache HTTP Server versions 2.4.20–2.4.43. A specially crafted value for the Cache-Digest header in an HTTP/2 request could cause a crash when the server subsequently attempts to HTTP/2 PUSH a resource. Mitigation for unpatched servers is to disable HTTP/2 PUSH via H2Push of...

CVE-2020-11993

CVE-2020-11993 affects Apache HTTP Server 2.4.20–2.4.43: when trace/debug is enabled for the HTTP/2 module and certain traffic patterns, logging can be performed on the wrong connection, leading to concurrent use of memory pools. Mitigation in public advisories: set LogLevel for mod_http2 above i...

CVE-2017-15710

The CVE-2017-15710 issue affects Apache httpd when mod_authnz_ldap is used with AuthLDAPCharsetConfig. A crafted Accept-Language header is looked up in a charset table; if not present, it is truncated to two characters, and values shorter than two characters trigger an out-of-bounds write of a NU...

CVE-2024-27316

CVE-2024-27316 affects the mod_http2 component used with Apache httpd; the issue occurs when HTTP/2 headers exceed the configured limit, causing nghttp2 to buffer headers and potentially leading to memory exhaustion if the client continues sending headers. Connected sources identify affected pack...

CVE-2020-35452

The CVE-2020-35452 entry concerns Apache HTTP Server 2.4.0–2.4.46, where a specially crafted Digest nonce can trigger a stack overflow in mod_auth_digest. The description notes there was no reported exploit against Apache at the time, though certain compiler/compile options might enable it with l...

CVE-2006-20001

CVE-2006-20001 affects Apache HTTP Server 2.4.54 and earlier. The issue is triggered by a crafted If: header that can read memory or write a single zero byte in heap memory beyond the header value, potentially crashing the process. Industry advisories confirm the vulnerability in Apache httpd and...

CVE-2016-8743

The CVE-2016-8743 issue affects Apache HTTP Server. It concerns how whitespace is accepted in requests and sent in response lines and headers in all releases before 2.2.32 and 2.4.25. The root problem is liberal whitespace handling, which can enable request smuggling, response splitting, and cach...

CVE-2022-22719

Summary (CVE-2022-22719) Affects Apache HTTP Server (httpd) 2.4.52 and earlier. The issue arises in the httpd mod_lua component where an uninitialized value in r:parsebody can cause a read to a random memory area, potentially leading to a crash and availability impact. Connected advisories confir...

CVE-2022-30556

The CVE-2022-30556 issue affects Apache HTTP Server (2.4.53 and earlier) where the wsread path may return a pointer past the end of the buffer, enabling information disclosure via websockets. Public references in connected sources corroborate: (1) industry advisories note an information disclosur...

CVE-2021-26690

CVE-2021-26690 affects Apache HTTP Server 2.4.0–2.4.46 due to a NULL pointer dereference in mod_session when parsing a crafted Cookie header, leading to Denial of Service. Public advisories and vendor pages confirm a patch exists in newer httpd releases (e.g., 2.4.46+/2.4.51 in various distributi...

CVE-2021-34798

CVE-2021-34798 is a vulnerability in Apache HTTP Server where malformed requests may cause a NULL pointer dereference in the httpd core. The issue affects Apache HTTP Server 2.4.48 and earlier, and the resulting crash can lead to a Denial of Service. Multiple connected advisories confirm the same...

CVE-2013-2249

CVE-2013-2249 concerns Apache HTTP Server’s mod_session_dbd. The issue arises when mod_session_dbd proceeds with save operations for a session without honoring the dirty flag or requiring a new session ID, as described in multiple sources. Public references indicate the vulnerability is associate...

CVE-2019-10081

CVE-2019-10081 affects Apache httpd's HTTP/2 implementation (mod_http2) where very early pushes can overwrite memory in the pushing request’s pool, causing crashes. The vulnerable facet is the handling of push headers (not client data) and memory being copied from the configured push link header ...

CVE-2022-26377

CVE-2022-26377 is a real HTTP Request Smuggling vulnerability in the mod_proxy_ajp module of Apache HTTP Server. Affected: Apache httpd 2.4.53 and earlier. Description across sources confirms that an attacker can smuggle requests to the AJP server to which httpd forwards traffic. Patches/updates ...

CVE-2021-33193

CVE-2021-33193 describes a vulnerability in Apache HTTP Server where a crafted HTTP/2 method can bypass validation and be forwarded by mod_proxy, potentially enabling request splitting or cache poisoning. The issue affects Apache httpd versions 2.4.17 through 2.4.48. Connected advisories and noti...

CVE-2016-0736

Apache HTTP Server versions 2.4.0 to 2.4.23 are vulnerable via the mod_session_crypto module. The component is susceptible to padding oracle attacks , particularly when using CBC mode of operation, because it lacks selectable or built-in authenticated encryption while encrypting data and cookies....

CVE-2022-29404

CVE-2022-29404 affects Apache HTTP Server 2.4.53 and earlier. The vulnerability lies in the mod_lua code path: a malicious request to a Lua script calling r:parsebody(0) can cause a denial of service due to no default input size limit. Impact is DoS (availability) with network exposure; no data c...

CVE-2016-2161

CVE-2016-2161 affects Apache HTTP Server 2.4.0–2.4.23 in the mod_auth_digest pathway. Malicious input to mod_auth_digest could cause the server to crash, and subsequent valid requests could still trigger crashes. The connected advisory pages confirm Apache’s fix to 2.4.25 (and related advisories)...

CVE-2023-27522

CVE-2023-27522 affects Apache HTTP Server (httpd) versions 2.4.30–2.4.55 via mod_proxy_uwsgi. The issue is HTTP Response Smuggling where special characters in the origin response header can truncate or split the response forwarded to the client. AlmaLinux and ALAS advisories explicitly reference ...

CVE-2019-10097

In Apache HTTP Server versions 2.4.32-2.4.39 , a vulnerability exists in the mod_remoteip module. When configured to use a trusted intermediary proxy server via the PROXY protocol, a specially crafted PROXY header can trigger a stack buffer overflow or NULL pointer deference . This issue can only...

CVE-2021-36160

CVE-2021-36160 affects Apache HTTP Server mod_proxy_uwsgi. A crafted request URI-path can cause mod_proxy_uwsgi to read beyond allocated memory, triggering a DoS. The issue is reported for Apache httpd versions 2.4.30–2.4.48. Public sources in connected documents corroborate the impact as an out-...

CVE-2023-31122

CVE-2023-31122 is an out-of-bounds read vulnerability in Apache HTTP Server’s mod_macro affecting versions up to 2.4.57. Connected advisories (Debian, AlmaLinux, Amazon Linux, CIRCL sighting) confirm multiple distro advisories have issued patches and upgrades (e.g., Debian 2.4.59 fixes; AlmaLinux...

CVE-2019-0215

CVE-2019-0215 affects Apache HTTP Server 2.4.37–2.4.38. A bug in mod_ssl for per-location client certificate verification with TLSv1.3 allowed bypass of configured access controls. Impact is access restriction bypass; no explicit exploitation details provided here. Remediation: upgrade to 2.4.39 ...

CVE-2024-38477

CVE-2024-38477 affects Apache HTTP Server 2.4.59 and earlier. The issue is a null pointer dereference in mod_proxy triggered by a malicious request, which can crash the server (Denial of Service). The published remediation is to upgrade to Apache HTTP Server 2.4.60, which fixes the issue. The CVE...

CVE-2018-1333

CVE-2018-1333 affects Apache HTTP Server. By specially crafting HTTP/2 requests, workers could be allocated 60 seconds longer than necessary, causing worker exhaustion and denial of service. Affected versions: 2.4.18–2.4.30 and 2.4.33; fixed in 2.4.34. The vulnerability originates from the HTTP/2...

CVE-2020-13950

CVE-2020-13950 affects Apache HTTP Server (httpd) mod_proxy_http, with versions 2.4.41–2.4.46 vulnerable to a NULL pointer dereference triggered by specially crafted requests using both Content-Length and Transfer-Encoding headers, causing Denial of Service. Connected documents confirm impact as ...

CVE-2018-1303

A specially crafted HTTP request header could cause the Apache HTTP Server (prior to version 2.4.30 ) to crash. The root cause is an out-of-bounds read occurring while preparing data to be cached in shared memory. This vulnerability specifically impacts users of the mod_cache_socache module and c...

CVE-2022-30522

CVE-2022-30522 affects Apache HTTP Server mod_sed; when input to mod_sed is very large, it can cause excessive memory allocations and aborts, impacting availability. The issue is documented across multiple feeds (e.g., CVE page for 2.4.53 context and later advisories) and is addressed by updating...

CVE-2024-39573

Apache HTTP Server versions 2.4.59 and earlier are vulnerable to a potential SSRF (Server-Side Request Forgery) in the mod_rewrite component. The root cause allows an attacker to trigger unsafe RewriteRules , which can unexpectedly cause URLs to be processed by mod_proxy . This issue has been add...

CVE-2024-38472

A Server-Side Request Forgery (SSRF) vulnerability exists in the Apache HTTP Server on Windows systems. The flaw allows an attacker to potentially leak NTLM hashes to a malicious server by sending malicious requests or content. To remediate this issue, users are recommended to upgrade to version ...

CVE-2009-1891

CVE-2009-1891 affects the Apache HTTP Server mod_deflate in 2.2.x (notably 2.2.11 and earlier). The issue causes CPU consumption DoS by compressing large files even after the client connection closes. Public advisories across distributions confirm the flaw and its remediation via updated packages...

CVE-2025-59775

A Server-Side Request Forgery (SSRF) vulnerability exists in Apache HTTP Server on Windows when AllowEncodedSlashes is enabled and MergeSlashes is disabled. This flaw allows an attacker to potentially leak NTLM hashes to a malicious server through SSRF via malicious requests or content. The vulne...

CVE-2021-31618

CVE-2021-31618 affects the Apache httpd mod_http2 component. The issue is a NULL pointer dereference in the HTTP/2 header handling when size limits are violated, leading to denial of service by crashing the httpd worker process. Affected releases include mod_http2 1.15.17 and Apache httpd 2.4.47 ...

CVE-2009-1890

CVE-2009-1890 affects Apache HTTP Server when used as a reverse proxy. The mod_proxy_http.c mechanism can fail to correctly bound a stream when Content-Length is exceeded, causing a denial-of-service via CPU exhaustion from crafted requests. The issue is specific to the reverse-proxy path in mod_...

CVE-2026-49975

The Apache HTTP Server is vulnerable to a Denial of Service (DoS) attack due to a memory allocation vulnerability with an excessive size value in the mod_http component. Specifically, this flaw allows for memory exhaustion via malicious HTTP requests, which can be triggered by a compression bomb ...

CVE-2023-43622

CVE-2023-43622 affects Apache HTTP Server via the mod_http2 implementation. An attacker opening an HTTP/2 connection with an initial window size of 0 could block handling of that connection indefinitely, potentially exhausting server worker resources in a pattern similar to the slow loris attack....

CVE-2016-4979

CVE-2016-4979 affects Apache HTTP Server 2.4.18–2.4.20 when mod_http2 and mod_ssl are enabled; it fails to recognize the SSLVerifyClient require directive for HTTP/2 request authorization, enabling bypass of access restrictions by abusing multiple requests on a single connection and renegotiation...

CVE-2025-53020

Apache HTTP Server versions 2.4.17 through 2.4.63 are vulnerable to a memory exhaustion denial of service (DoS) via the HTTP/2 implementation. The root cause is a late release of memory after its effective lifetime, specifically occurring when processing repeated header names in HTTP/2 requests. ...

CVE-2021-41524

CVE-2021-41524 affects Apache HTTP Server (httpd) 2.4.49, where a null pointer dereference during HTTP/2 request processing can allow external sources to cause a DoS. The flaw was introduced with 2.4.49; no public exploit is shown in the documents. Check Point’s November 2021 advisory maps this C...

CVE-2017-7659

A NULL pointer dereference vulnerability in the mod_http2 module of Apache HTTP Server versions 2.4.24 and 2.4.25 can be triggered by a maliciously constructed HTTP/2 request . This flaw allows a remote attacker to cause the server process to crash, resulting in a denial of service. Impacted prod...

CVE-2016-8740

CVE-2016-8740 affects Apache HTTP Server mod_http2 when Protocols includes h2/h2c. A memory-exhaustion DoS arises from improper restriction of request-header length in crafted CONTINUATION frames in versions 2.4.17–2.4.23. Connected sources confirm the root cause is header-length handling without...

CVE-1999-0236

The CVE-1999-0236 entry describes a vulnerability in the ScriptAlias directory handling in NCSA and Apache httpd that allowed attackers to read CGI programs. Affected software is the Apache httpd family utilizing ScriptAlias configuration; the underlying issue is directory handling enabling discl...