spdystream vulnerability

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.

Published 16 Apr 2026Updated 7 Sep 202687 sources
CVSS 8.7

What happened

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.

Affected versions

spdystream: < 0.5.1 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.