CVE-2026-35469

spdystream is a Go library for multiplexing streams over SPDY connections. In versions 0.5.0 and below, the SPDY/3 frame parser does not validate attacker-controlled counts and lengths before allocating memory. Three allocation paths are affected: the SETTINGS frame entry count, the header count in parseHeaderValueBlock, and individual header field sizes — all read as 32-bit integers and used directly as allocation sizes with no bounds checking. Because SPDY header blocks are zlib-compressed, a small on-the-wire payload can decompress into large attacker-controlled values. A remote peer that can send SPDY frames to a service using spdystream can exhaust process memory and cause an out-of-memory crash with a single crafted control frame. This issue has been fixed in version 0.5.1.

The SPDY/3 frame parser in spdystream does not validate attacker-controlled counts and lengths before allocating memory. A remote peer that can send SPDY frames to a service using spdystream can cause the process to allocate gigabytes of memory with a small number of malformed control frames, leading to an out-of-memory crash. Three allocation paths in the receive side are affected: 1. SETTINGS entry count: The SETTINGS frame reader reads a 32-bit numSettings from the payload and allocates a slice of that size without checking it against the declared frame length. 2. Header count: parseHeaderValueBlock reads a 32-bit numHeaders from the decompressed header block and allocates an http.Header map of that size with no upper bound. 3. Header field size: Individual header name and value lengths are read as 32-bit integers and used directly as allocation sizes with no validation. Because SPDY header blocks are zlib-compressed, a small on-the-wire payload can decompress into attacker-controlled bytes that the parser interprets as 32-bit counts and lengths. A single crafted frame is enough to exhaust process memory.

The SPDY/3 frame parser in spdystream does not validate attacker-controlled counts and lengths before allocating memory. A remote peer that can send SPDY frames to a service using spdystream can cause the process to allocate gigabytes of memory with a small number of malformed control frames, leading to an out-of-memory crash.   Three allocation paths in the receive side are affected: 1. **SETTINGS entry count** -- The SETTINGS frame reader reads a 32-bit `numSettings` from the payload and allocates a slice of that size without checking it against the declared frame length. An attacker can set `numSettings` to a value far exceeding the actual payload, triggering a large allocation before any setting data is read.   2. **Header count** -- `parseHeaderValueBlock` reads a 32-bit `numHeaders` from the decompressed header block and allocates an `http.Header` map of that size with no upper bound.   3. **Header field size** -- Individual header name and value lengths are read as 32-bit integers and used directly as allocation sizes with no validation.   Because SPDY header blocks are zlib-compressed, a small on-the-wire payload can decompress into attacker-controlled bytes that the parser interprets as 32-bit counts and lengths. A single crafted frame is enough to exhaust process memory. ## Impact  Any program that accepts SPDY connections using spdystream -- directly or through a dependent library -- is affected. A remote peer that can send SPDY frames to the service can crash the process with a single crafted SPDY control frame, causing denial of service. ## Affected versions  `github.com/moby/spdystream` <= v0.5.0 ## Fix  v0.5.1 addresses the receive-side allocation bugs and adds related hardening:   **Core fixes:**   - **SETTINGS entry-count validation** -- The SETTINGS frame reader now checks that `numSettings` is consistent with the declared frame length (`numSettings <= (length-4)/8`) before allocating.   - **Header count limit** -- `parseHeaderValueBlock` enforces a maximum number of headers per frame (default: 1000).   - **Header field size limit** -- Individual header name and value lengths are checked against a per-field size limit (default: 1 MiB) before allocation.   - **Connection closure on protocol error** -- The connection read loop now closes the underlying `net.Conn` when it encounters an `InvalidControlFrame` error, preventing further exploitation on the same connection.   **Additional hardening:**   - **Write-side bounds checks** -- All frame write methods now verify that payloads fit within the 24-bit length field, preventing the library from producing invalid frames.   **Configurable limits:**   - Callers can adjust the defaults using `NewConnectionWithOptions` or the lower-level `spdy.NewFramerWithOptions` with functional options: `WithMaxControlFramePayloadSize`, `WithMaxHeaderFieldSize`, and `WithMaxHeaderCount`.