CVE-2016-4864

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2017-05-12 · updated 2026-06-17
Weakness: CWE-134

Description

H2O versions 2.0.3 and earlier and 2.1.0-beta2 and earlier allows remote attackers to cause a denial-of-service (DoS) via format string specifiers in a template file via fastcgi, mruby, proxy, redirect or reproxy.

Affected products

h2o: from 2.0.0 through 2.0.3; 2.1.0, 2.1.0-beta1

References

https://github.com/h2o/h2o/issues/1077
https://jvn.jp/en/jp/JVN94779084/index.html
https://github.com/h2o/h2o/issues/1077
https://jvn.jp/en/jp/JVN94779084/index.html

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