When parsing request variables such as query-string and form parameters, HHVM did not check that appending a nested array succeeded before descending into it. A remote, unauthenticated attacker could send a GET or POST request which would crash the HHVM server process before any application code runs, leading to denial of service. This issue affected HHVM prior to 23c061f4e804a51badd5f85227e65185651253b5.

proxygen's HTTP/3 codec buffered an incomplete non-DATA frame, such as a control-stream frame, a frame of an unknown or reserved type, or a HEADERS frame, until its entire declared length had arrived, without limiting that length, and re-scanned all buffered data each time more bytes arrived. A remote, unauthenticated HTTP/3 peer could declare a very large frame and deliver it slowly, causing unbounded memory growth and CPU usage that grows quadratically with the number of fragments, leading to denial of service. This issue affects proxygen versions prior to v2026.11.09.00.

proxygen's QPACK decoder enforced its size limit on a string literal in an encoder-stream instruction only after the entire literal had been received. A remote, unauthenticated HTTP/3 peer could send an insert instruction on the QPACK encoder stream that declares an arbitrarily large literal and then keep sending data, causing the decoder to buffer it without bound for the lifetime of the connection and exhaust memory, leading to denial of service. The issue occurs regardless of the advertised QPACK dynamic table capacity, including when the dynamic table is disabled. This issue affects proxygen versions prior to v2026.11.09.00.

In proxygen's HTTP/3 session, when a HEADERS block referenced QPACK dynamic table entries that had not yet been received, header decoding for that stream was paused, but the session continued to read the stream from the QUIC transport. The unread data bypassed the session's ingress buffer limit, returned flow-control credit to the peer, and was re-scanned in full on every read. With QPACK blocked streams enabled (the default), a remote, unauthenticated HTTP/3 peer could send a HEADERS block that references a dynamic table insert it never sends, followed by a continuous stream of data, causing memory growth until the request timed out and CPU usage that grows quadratically, leading to denial of service. This issue affects proxygen versions prior to v2026.11.09.00.

mvfst did not adequately merge or compact out-of-order STREAM frame data, and a small received fragment could keep a much larger receive buffer alive. QUIC flow control limits the number of buffered stream bytes, but not this per-fragment memory and bookkeeping. A remote, unauthenticated QUIC peer could send many small, non-contiguous stream fragments to make an endpoint consume memory far in excess of its advertised receive window and spend increasing CPU time reassembling stream data, leading to denial of service. This issue affects mvfst versions prior to v2026.11.09.0.

An mvfst QUIC server retained CRYPTO frame data received at an encryption level (Initial or Handshake) that the TLS handshake had already moved past. Because the transport treated this data as delivered, it did not count against the CRYPTO stream buffer limit. A remote, unauthenticated client could complete a handshake, withhold its acknowledgment of the server's HANDSHAKE_DONE frame so that Handshake keys stay in use, and keep sending Handshake-level CRYPTO data at increasing offsets, causing unbounded memory growth on the server and leading to denial of service. This issue affects mvfst versions prior to v2026.11.09.00.

Server Crash and Possible Memory Corruption via Pipelined HTTP/1.1 Requests in Facebook Proxygen

When a remote, unauthenticated HTTP/1.1 client pipelined the start of a second request and then stopped reading, proxygen's coroutine-based HTTP session could free that pipelined stream while resetting the connection's streams on the resulting write timeout, then go on to use it. This can crash the server, leading to denial of service, and may allow memory corruption with further impact. This issue affects proxygen versions prior to v2026.11.09.00.

zstd: Race condition allows attacker to access world-readable destination file

Beginning in v1.4.1 and prior to v1.4.9, due to an incomplete fix for CVE-2021-24031, the Zstandard command-line utility created output files with default permissions and restricted those permissions immediately afterwards. Output files could therefore momentarily be readable or writable to unintended parties.

In proxygen from v2026.04.06.00 until v2026.09.28.00, QuicWtSession::closeSession accesses its member fields after calling the base QuicWtSessionBase::closeSession method. The base method notifies the session handler, which may release the last reference to the session and destroy it.

In proxygen from v2024.10.28.00 until v2026.09.28.00, WebTransportImpl::terminateSessionStreams (WebTransportImpl::destroy in releases before v2025.08.18.00) failed to unregister read callbacks for streams that were no longer open before destroying them. The transport could then invoke a read callback that had been freed.

In proxygen from v2024.10.28.00 until v2026.09.28.00, the HTTPTransaction::onWebTransportUniStream and HTTPTransaction::onWebTransportBidiStream APIs could return stream handles that the stream handler had already freed. HQSession then installed those handles as transport read callbacks, which could lead to use of freed memory.

Denial of Service via Crafted HTTP Requests in Meta’s React Server DOM Packages

A denial of service vulnerability could be triggered by sending specially crafted HTTP requests to server function endpoints, this could lead to server crashes, out-of-memory exceptions or excessive CPU usage; affecting the following packages: react-server-dom-webpack, react-server-dom-parcel, react-server-dom-turbopack (versions 19.0.0 through 19.0.5, 19.1.0 through 19.1.6, and 19.2.0 through 19.2.5).

HTTP/2: Multiple HTTP/2 enabled web servers are vulnerable to a DDoS attack (Rapid Reset Attack)

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

WordPress Facebook for WordPress plugin <= 5.2.1 - Cross Site Scripting (XSS) vulnerability

Unauthenticated Cross Site Scripting (XSS) in Facebook for WordPress <= 5.2.1 versions.

WordPress Facebook for WooCommerce plugin <= 3.7.5 - Cross Site Scripting (XSS) vulnerability

Unauthenticated Cross Site Scripting (XSS) in Facebook for WooCommerce <= 3.7.5 versions.

Excessive CPU Resource Exhaustion Denial of Service in Meta's React Server DOM Packages

A denial of service vulnerability could be triggered by sending specially crafted HTTP requests to server function endpoints, this could lead to excessive CPU usage; affecting the following packages: react-server-dom-webpack, react-server-dom-parcel, react-server-dom-turbopack (versions 19.0.0 through 19.0.7, 19.1.0 through 19.1.8, and 19.2.0 through 19.2.7).

HTTP/2 Flow‑Control Exploit Causes Unbounded Memory Growth in Proxygen

Proxygen lacked a generalized slow-consumer detection mechanism in its core HTTP session layer. A remote, unauthenticated attacker could exploit HTTP/2 flow-control by setting SETTINGS_INITIAL_WINDOW_SIZE to 0 or withholding WINDOW_UPDATE frames, causing the server to buffer complete response bodies in memory indefinitely for stalled streams. By opening many simultaneous streams requesting large resources while preventing the server from transmitting responses, an attacker could induce unbounded memory growth leading to service degradation, resource exhaustion, or denial of service. Versions v2017.01.16.00 through v2026.07.20.00 are affected.

react create-react-app react-dev-utils openBrowser.js startBrowserProcess os command injection

A vulnerability was detected in react create-react-app up to 5.0.1 on macOS. This affects the function startBrowserProcess of the file openBrowser.js of the component react-dev-utils. Performing a manipulation results in os command injection. Remote exploitation of the attack is possible. The exploit is now public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

WordPress Facebook for WooCommerce plugin <= 3.7.0 - Open Redirection vulnerability

URL Redirection to Untrusted Site ('Open Redirect') vulnerability in Facebook Facebook for WooCommerce allows Phishing. This issue affects Facebook for WooCommerce: from n/a through 3.7.0.

WordPress Facebook for WooCommerce plugin <= 3.5.7 - Broken Access Control to Notice Dismissal vulnerability

Missing Authorization vulnerability in Facebook Facebook for WooCommerce facebook-for-woocommerce allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects Facebook for WooCommerce: from n/a through <= 3.5.7.