CVE-2026-59803

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.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.7% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-25)

CWE

CWE-409

Published

2026-07-08

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

References

• https://github.com/smallnest/rpcx/commit/047aec18efa7d037105e2b72c36dd2ae05e1acc6
• https://github.com/smallnest/rpcx/issues/942
• https://github.com/smallnest/rpcx/pull/943
• https://www.vulncheck.com/advisories/rpcx-denial-of-service-via-gzip-decompression-bomb-in-wire-protocol

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