CVE-2026-6994

Envoy Query Parameter header_mutation.cc params.add injection

5.3 Medium

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: Low

Exploit likelihood

0.23%Up 0.2 points since Apr 26, 2026

What each source reports

CVE List Score used 5.3

Envoy Query Parameter header_mutation.cc params.add injection

Record: CVE-2026-6994
CVSS 4.0: 5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:X/RL:O/RC:C
CVSS 3.0: 6.3 MediumCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:X/RL:O/RC:C
CVSS 2.0: 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P/E:ND/RL:OF/RC:C
Weakness: CWE-74, CWE-707
Updated: 2026-11-02

EUVDEUVD-2026-25670 5.3

Record: EUVD-2026-25670
CVSS 4.0: 5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
Updated: 2026-11-02

GitHub AdvisoriesGHSA-42r9-gr9r-q5q5 5.3

A weakness has been identified in Envoy up to 1.33.0. Affected is the function params.add of the...

Record: GHSA-42r9-gr9r-q5q5
CVSS 4.0: 5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Weakness: CWE-74
Updated: 2026-11-02

NVD 5.3

Record: CVE-2026-6994
CVSS 4.0: 5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CVSS 2.0: 6.5 MediumAV:N/AC:L/Au:S/C:P/I:P/A:P
Weakness: CWE-74, CWE-707
Updated: 2026-11-02

OSV 5.3

Envoy Query Parameter header_mutation.cc params.add injection

Record: CVE-2026-6994
CVSS 4.0: 5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
Weakness: CWE-707, CWE-74
Updated: 2026-11-02

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-6994 is a medium vulnerability (CVSS 5.3), published April 25, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.23%, the 13th percentile. No source names a fixed version.