CVE-2026-26309
Envoy has an off-by-one write in JsonEscaper::escapeString()
CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-193 |
| Vendor | envoyproxy |
| Product | envoy |
| Published | Mar 10, 2026 |
| Last Updated | Mar 10, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
Affected Versions
envoyproxy / envoy
>= 1.37.0, < 1.37.1 >= 1.36.0, < 1.36.5 >= 1.35.0, < 1.35.9 < 1.34.13