Envoy
CVE-2026-26309
MEDIUM
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Lifecycle Timeline
3DescriptionGitHub Advisory
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.
AnalysisAI
Envoy is a high-performance edge/middle/service proxy. [CVSS 5.3 MEDIUM]
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Vulnerability AssessmentAI
| Risk Assessment | CVSS 5.3 (MEDIUM). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker could exploit this flaw, crashes or out-of-bounds reads when the resulting string is. |
| Remediation | Fixed in version 1.37.1. … Detailed patch versions, workarounds, and compensating controls in full report. |
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External POC / Exploit Code
Leaving vuln.today
GHSA-56cj-wgg3-x943