CVE-2021-35063

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

7.5 HighFix available

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Attack profile

How easy it is to exploit

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

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

2.05%Up 0.8 points since Jul 23, 2021

What each source reports

NVD Score used 7.5

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: CVE-2021-35063
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Updated: 2026-11-02

CVE List No score

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: CVE-2021-35063
Updated: 2026-11-02

EUVDEUVD-2021-21708 No score

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: EUVD-2021-21708
Updated: 2026-11-03

GitHub AdvisoriesGHSA-h9v2-m5qx-h268 No score

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: GHSA-h9v2-m5qx-h268
Updated: 2026-11-02

OSVALPINE-CVE-2021-35063 7.5

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: ALPINE-CVE-2021-35063
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

OSV 7.5

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: CVE-2021-35063
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-35063 7.5

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: DEBIAN-CVE-2021-35063
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-35063 7.5

Suricata before 5.0.7 and 6.x before 6.0.3 has a "critical evasion."

Record: UBUNTU-CVE-2021-35063
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVMGASA-2022-0008 No score

Updated suricata packages fix security vulnerability

Critical evasion in suricata (CVE-2021-35063)

Record: MGASA-2022-0008
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`suricata` Alpine:v3.14	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.15	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.16	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.17	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.18	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.19	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.20	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.21	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.22	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Alpine:v3.23	6.0.0 up to 6.0.3-r0	6.0.3-r0

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Affected packages
Package	Affected	Fixed
`suricata` Alpine:v3.24	6.0.0 up to 6.0.3-r0	6.0.3-r0
`suricata` Debian:13	before 1:6.0.1-3	1:6.0.1-3
`suricata` Debian:14	before 1:6.0.1-3	1:6.0.1-3
`suricata` Mageia:8	before 6.0.4-1.mga8	6.0.4-1.mga8
`suricata` Ubuntu:16.04:LTS	All versions, plus listed versions 2.0.8-1build12.0.9-12.0.10-12.0.10-22.0.11-13.0-1	None known
`suricata` Ubuntu:18.04:LTS	All versions, plus listed versions 3.2-2ubuntu3	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	affected, aliases, references	OSV
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

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

In short

CVE-2021-35063 is a high vulnerability (CVSS 7.5) in Oisf Suricata, published July 22, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.05%, the 81st percentile. Fixed in suricata 6.0.3-r0.

References

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