CVE-2025-8671

Secure, fast, compliant and very flexible web-server which has been optimized for high-performance environments. It has a very low memory footprint compared to other webservers and takes care of cpu-load. Its advanced feature-set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) make it the perfect webserver-software for every server that is suffering load problems.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

Secure, fast, compliant and very flexible web-server which has been optimized for high-performance environments. It has a very low memory footprint compared to other webservers and takes care of cpu-load. Its advanced feature-set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) make it the perfect webserver-software for every server that is suffering load problems.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

This is Varnish Cache, a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

This is Varnish Cache, a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

This is Varnish Cache, a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

This is Varnish Cache, a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

This is Varnish Cache, a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

Secure, fast, compliant and very flexible web-server which has been optimized for high-performance environments. It has a very low memory footprint compared to other webservers and takes care of cpu-load. Its advanced feature-set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) make it the perfect webserver-software for every server that is suffering load problems.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

This is Varnish Cache, a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

Secure, fast, compliant and very flexible web-server which has been optimized for high-performance environments. It has a very low memory footprint compared to other webservers and takes care of cpu-load. Its advanced feature-set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) make it the perfect webserver-software for every server that is suffering load problems.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

Secure, fast, compliant and very flexible web-server which has been optimized for high-performance environments. It has a very low memory footprint compared to other webservers and takes care of cpu-load. Its advanced feature-set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) make it the perfect webserver-software for every server that is suffering load problems.

Security Fix(es):

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.(CVE-2025-8671)

A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.

It was discovered that a denial of service attack can be performed on cache servers that have the HTTP/2 protocol turned on. An attacker can create a large number of streams and immediately reset them without ever reaching the maximum number of concurrent streams allowed for the session, causing the server to consume unnecessary resources processing requests for which the response will not be delivered (CVE-2025-8671).

These are all security issues fixed in the lighttpd-1.4.80-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the dnsdist-2.0.2-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the bun-1.4.4-1.1 package on the GA media of openSUSE Tumbleweed.

This update for dnsdist fixes the following issues:

Update to dnsdist 1.9.11:

• CVE-2025-8671: add mitigations for the HTTP/2 MadeYouReset attack (bsc#1253852).
• CVE-2025-30187: denial of service via crafted DoH exchange (bsc#1250054).

This update for varnish fixes the following issues:

Changes in varnish:

• update to 7.7.3 (bsc#1280114, CVE-2025-8671):

  • https://vinyl-cache.org/docs/7.7/whats-new/changes-7.7.html
  • https://vinyl-cache.org/security/VSV00017.html#vsv00017

• Update to release 7.7.1

  • VSV-16: Resolve request smuggling attack

• Update to release 7.7.0

  • The linux jail gained control of transparent huge pages settings.
  • An issue has been fixed which could cause a crash when varnishd receives an invalid Content-Range header from a backend.
  • Timestamping for HTTP/2 requests (when idle period begins) has been switched to be more in line with HTTP/1.
  • VSV-15: The client connection is now always closed when a malformed request is received. [CVE-2025-30346, boo#1239892]

Pingora deployments using versions prior to 0.6.0 that include HTTP/2 server support may be affected by the vulnerability described in CVE-2025-8671. Under certain conditions, Pingora applications may allocate buffers before the HTTP/2 reset and resulting stream cancellation is processed by the server. Repeated resets can force excessive memory consumption and lead to denial-of-service.

On affected versions, malicious clients could trigger unusually high memory consumption, which may result in service instability or process termination.

This issue is addressed by ensuring Pingora uses patched versions of HTTP/2 dependencies that include reset-handling safeguards to release connection resources before excessive memory buildup. Users are requested to upgrade to versions >= 0.6.0, which incorporates the required fixes.

This update for dnsdist fixes the following issues:

Update to dnsdist 1.9.11:

• CVE-2025-8671: Add mitigations for the HTTP/2 MadeYouReset attack (bsc#1253852).
• CVE-2025-30187: denial of service via crafted DoH exchange (bsc#1250054).

This update for dnsdist fixes the following issues:

Update to dnsdist 1.9.11:

• CVE-2025-8671: add mitigations for the HTTP/2 MadeYouReset attack (bsc#1253852).
• CVE-2025-30187: denial of service via crafted DoH exchange (bsc#1250054).

It was discovered that HTTP/2, which is used/vendored by DNSdist, did not properly account for resources when handling client-triggered stream resets. An attacker could possibly use this issue to cause a denial of service. (CVE-2025-8671)

It was discovered that DNSdist did not properly manage memory limits when handling an unlimited number of queries on a single TCP connection. An attacker could possibly use this issue to cause a denial of service. (CVE-2025-30193)

It was discovered that DNSdist, when configured with the nghttp2 library, did not correctly process certain DNS over HTTPS queries. An attacker could possibly use this cause a denial of service. (CVE-2025-30187)