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Fencer Intel
medium 5.9

CVE-2018-6332 json

A potential denial-of-service issue in the Proxygen handling of invalid HTTP2 settings which can cause the server to spend disproportionate…

published 7y ago modified 4mo ago also EUVD-2018-18093

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

A potential denial-of-service issue in the Proxygen handling of invalid HTTP2 settings which can cause the server to spend disproportionate resources. This affects all supported versions of HHVM (3.24.3 and 3.21.7 and below) when using the proxygen server to handle HTTP2 requests.

Patch / fix

  • Facebook HHVM 3.21.8

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

1.09% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.0 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Affected products

  • Facebook HHVM

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-19 Data Processing Errors

References

Sources

Fencer Intel 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.