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Fencer Vulns
medium 6.3

CVE-2026-6994 json

Envoy Query Parameter header_mutation.cc params.add injection

published 2026-04-25 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-25670

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

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.

Patch / fix

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-6994 updated cvss 6.3

envoy: Envoy: Injection vulnerability in Query Parameter Handler

  • Red Hat OpenShift Service Mesh 2 openshift-service-mesh/proxyv2-rhel9 Red Hat OpenShift Service Mesh 3 openshift-service-mesh/istio-proxyv2-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS: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
CNA 3.1 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:X/RL:O/RC:C
CNA 3.0 6.3 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:X/RL:O/RC:C
CNA 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P/E:ND/RL:OF/RC:C
CNA 4.0 5.3 CVSS: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
CNA 3.1 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CNA 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P

Affected products

  • n/a Envoy

Classification

Weakness
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component
  • CWE-707 Improper Neutralization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.