Query parameter injection via unencoded formatter values
Published Apr 25, 2026 · Updated Apr 25, 2026
Query parameter injection in Envoy 1.33.0 and earlier allows remote authenticated users to alter upstream request query strings. The header mutation filter passes formatter-derived query values to params.add without URL encoding, so reserved delimiters become new parameters. Reachability requires query_parameter_mutations to consume attacker-influenced request data; injected parameters can change downstream request semantics.
Summary
What happened
Query parameter injection in Envoy 1.33.0 and earlier allows remote authenticated users to alter upstream request query strings. The header mutation filter passes formatter-derived query values to params.add without URL encoding, so reserved delimiters become new parameters. Reachability requires query_parameter_mutations to consume attacker-influenced request data; injected parameters can change downstream request semantics.
The record
- CVE
- CVE-2026-6994
- Published
- Apr 25, 2026
- Updated
- Apr 25, 2026
- Vendor
- Envoy Proxy
- Product
- Envoy
- Classifications
- CWE-74, CWE-707, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 25, 2026CVE publishedPublication date reported by the CVE source.
- Apr 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.0
- Affected versionversion=1.1
- Affected versionversion=1.10
- Affected versionversion=1.11
- Affected versionversion=1.12
- Affected versionversion=1.13
- Affected versionversion=1.14
- Affected versionversion=1.15
- Affected versionversion=1.16
- Affected versionversion=1.17
- Affected versionversion=1.18
- Affected versionversion=1.19
- Affected versionversion=1.2
- Affected versionversion=1.20
- Affected versionversion=1.21
- Affected versionversion=1.22
- Affected versionversion=1.23
- Affected versionversion=1.24
- Affected versionversion=1.25
- Affected versionversion=1.26
- Affected versionversion=1.27
- Affected versionversion=1.28
- Affected versionversion=1.29
- Affected versionversion=1.3
- Affected versionversion=1.30
- Affected versionversion=1.31
- Affected versionversion=1.32
- Affected versionversion=1.33.0
- Affected versionversion=1.4
- Affected versionversion=1.5
- Affected versionversion=1.6
- Affected versionversion=1.7
- Affected versionversion=1.8
- Affected versionversion=1.9
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo