Vulnerability record · CVE-2026-59803 · published 8 July 2026
CVE-2026-59803: rpcx through 1.9.3, fixed in commit 047aec1, contains a denial-of-service vulnerability in protocol.Message.De…
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.
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.
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:
References
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Source: NIST National Vulnerability Database (record CVE-2026-59803), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
