Quick answers
- Is CVE-2026-78048 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-78048 being exploited in the wild.
- How severe is CVE-2026-78048?
- Informational severity, published 21 October 2026.
- Which products and versions are affected?
- Apache Brpc < 1.18.0.
- Is there a fix for CVE-2026-78048?
- Yes: fixed in 1.18.0. Until then: Restrict HTTP/2 and gRPC traffic to trusted sources only via network-level access controls until bRPC can be upgraded.</anigation> <parameter name="timeline">[{"kind": "disclosed", "at": "2026-10-21"}] Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-78048 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-78048?
- Check whether you run Apache Brpc at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 1.18.0
Restrict HTTP/2 and gRPC traffic to trusted sources only via network-level access controls until bRPC can be upgraded.</anigation> <parameter name="timeline">[{"kind": "disclosed", "at": "2026-10-21"}]
Technical details
The HPACK decoder in src/brpc/details/hpack.cpp incorrectly sizes the dynamic table ring buffer based on a 34-byte minimum entry assumption, contradicting RFC 7541's 33-byte minimum. An attacker can add 121 minimal entries to the 4096-byte default table (consuming ~3993 bytes), triggering a buffer-full CHECK() assertion on the 121st header that aborts the process. The vulnerability is exploitable remotely over HTTP/2 or gRPC without authentication.
Affected products
- Apache bRPC < 1.18.0