CVE-2026-26309GHSA-56CJ-WGG3-X943BIT-ENVOY-2026-26309
Envoy has an off-by-one write in JsonEscaper::escapeString()
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 1.37.1, 1.36.5, 1.35.9, 1.34.13
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- envoyproxy envoy
From 1.37.0 · fixed in 1.37.1; From 1.36.0 · fixed in 1.36.5; From 1.35.0 · fixed in 1.35.9; fixed in 1.34.13
- github.com/envoyproxy/envoyGo
1.37.0
- github.com/envoyproxy/envoyGo
From 1.36.0 · through 1.36.4
- github.com/envoyproxy/envoyGo
From 1.35.0 · through 1.35.8
- github.com/envoyproxy/envoyGo
through 1.34.12