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Fencer Vulns
high 7.5

CVE-2021-36154 json

Uncontrolled Recursion in HTTP2ToRawGRPCServerCodec

published 2021-07-09 5 y ago modified 2026-07-08 4 mo ago also EUVD-2023-1469 , GHSA-4rhq-vq24-88gw

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

HTTP2ToRawGRPCServerCodec in gRPC Swift 1.1.1 and earlier allows remote attackers to deny service via the delivery of many small messages within a single HTTP/2 frame, leading to Uncontrolled Recursion and stack consumption.

Patch / fix

  • swift github.com/grpc/grpc-swift 1.2.0

Exploit prediction

2.08% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected packages

ecosystem package affected fixed in
swift github.com/grpc/grpc-swift
<1.2.0
1.2.0

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.