CVE-2026-26309
Last modified
CVE-2026-26309 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. EPSS estimates a 0.36% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Envoyproxy | Envoy | < 1.34.13 |
| Envoyproxy | Envoy | >= 1.35.0, < 1.35.8 |
| Envoyproxy | Envoy | >= 1.36.0, < 1.36.5 |
| Envoyproxy | Envoy | 1.37.0 |
References
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-56cj-wgg3-x943Exploit, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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