Vulnerability in Envoy
CVE-2026-6994
A weakness has been identified in Envoy up to 1.33.0. Affected is the function params.add of the file source/extensions/filters/http/header_mutation/header_mutation.cc of the component Query Parameter Handler. This manipulation causes injection. Remote exploitation of the attack is possible. Patch name: f8f4f1e02fdc64ecd4acf2d903208dd7285ad3a4. It is suggested to install a patch to address this issue.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.004 (30.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Envoy — versions 1.0, 1.1, 1.2
Weakness classification (CWE)
References
- vuldb.com/vuln/359546 (technical-description, vdb-entry)
- vuldb.com/vuln/359546/cti (signature, permissions-required)
- vuldb.com/submit/797241 (third-party-advisory)
- github.com/envoyproxy/envoy/pull/43502/ (issue-tracking, patch)
- github.com/envoyproxy/envoy/commit/f8f4f1e02fdc64ecd4acf2d903208dd7285ad3a4 (patch)
Frequently asked questions
- What is CVE-2026-6994?
- CVE-2026-6994 is a medium-severity vulnerability in Envoy, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.3/10. Published 2026-04-25.
- How severe is CVE-2026-6994?
- Medium severity. CVSS v3 base score is 6.3 out of 10.