Envoy is a high-performance edge/middle/service proxy. Prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13, an off-by-one write in Envoy::JsonEscaper::escapeString() can corrupt std::string null-termination, causing undefined behavior and potentially leading to crashes or out-of-bounds reads when the resulting string is later treated as a C-string. This vulnerability is fixed in 1.37.1, 1.36.5, 1.35.8, and 1.34.13.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-56cj-wgg3-x943 Envoy affected by off-by-one write in JsonEscaper::escapeString()
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 10 Mar 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 10 Mar 2026 19:30:00 +0000

Type Values Removed Values Added
Description Envoy is a high-performance edge/middle/service proxy. Prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13, an off-by-one write in Envoy::JsonEscaper::escapeString() can corrupt std::string null-termination, causing undefined behavior and potentially leading to crashes or out-of-bounds reads when the resulting string is later treated as a C-string. This vulnerability is fixed in 1.37.1, 1.36.5, 1.35.8, and 1.34.13.
Title Envoy has an off-by-one write in JsonEscaper::escapeString()
Weaknesses CWE-193
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-10T20:12:40.483Z

Reserved: 2026-02-13T16:27:51.805Z

Link: CVE-2026-26309

cve-icon Vulnrichment

Updated: 2026-03-10T20:11:56.525Z

cve-icon NVD

Status : Received

Published: 2026-03-10T20:16:35.880

Modified: 2026-03-10T20:16:35.880

Link: CVE-2026-26309

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses