Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service

Summary

Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service. The attacker sends a stream of headers with a 0-length header name and 0-length header value, optionally Huffman encoded into 1-byte or greater headers. Some implementations allocate memory for these headers and keep the allocation alive until the session dies. This can consume excess memory.

Timeline

1. Aug 13, 2019, 8:50 PM UTCCVE published
2. Aug 4, 2024, 9:54 PM UTCRecord last updated
3. Oct 28, 2026EPSS reached 10%

   FIRST estimates at least a 10% chance of exploitation in the next 30 days

Affected versions

• n/a n/a

  Version range not reported

References 25