CVE-2024-53271: HTTP/1.1 multiple issues with envoy.reloadable_features.http1_balsa_delay_reset in envoy

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2024-12-18 · updated 2026-06-17
Weakness: CWE-670

Description

Envoy is a cloud-native high-performance edge/middle/service proxy. In affected versions envoy does not properly handle http 1.1 non-101 1xx responses. This can lead to downstream failures in networked devices. This issue has been addressed in versions 1.31.5 and 1.32.3. Users are advised to upgrade. There are no known workarounds for this issue.

Affected products

envoyproxy envoy: from 1.31.0 before 1.31.5; from 1.32.0 through 1.32.3 — fixed in 1.31.5

How to fix

Upgrade to a fixed version: envoyproxy envoy 1.31.5. Check the vendor advisory for mitigations.

References

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