Description
rpcx through 1.9.3, fixed in commit 047aec1, contains a denial-of-service vulnerability in protocol.Message.Decode (protocol/message.go). When a message has the compression flag set, the payload is gzip-decompressed via util.Unzip with no limit on the decompressed output size. The only built-in size guard, protocol.MaxMessageLength, is checked against the compressed on-the-wire frame length, not the decompressed size, so it provides no protection. Because decoding (and decompression) occurs in readRequest before authentication, a single unauthenticated connection can send a small (under 2 MB) gzip-compressed message that expands to gigabytes of heap allocation, leading to out-of-memory conditions and service unavailability.
Severity (CVSS)
| Base score | 8.7 |
|---|---|
| Severity | High |
| Version | CVSS 4.0 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| Provided by | CNA |
Weaknesses
- CWE-409 — Improper Handling of Highly Compressed Data (Data Amplification)
Affected products
| Vendor | Product | Versions |
|---|---|---|
| smallnest | rpcx | 0 to <=1.9.3; 047aec18efa7d037105e2b72c36dd2ae05e1acc6 |
References
- https://github.com/smallnest/rpcx/issues/942 (technical-description exploit)
- https://github.com/smallnest/rpcx/pull/943 (issue-tracking)
- https://github.com/smallnest/rpcx/commit/047aec18efa7d037105e2b72c36dd2ae05e1acc6 (patch)
- https://www.vulncheck.com/advisories/rpcx-denial-of-service-via-gzip-decompression-bomb-in-wire-protocol (third-party-advisory)
Generated from the official CVE List on 09 Jul 2026 07:08 UTC.