What is CVE-2020-35498?

CVE-2020-35498 is a high-severity vulnerability in Openvswitch, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2021-02-11.

How severe is CVE-2020-35498?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2020-35498 known to be exploited?

6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Resource exhaustion in Openvswitch

CVE-2020-35498

A vulnerability was found in openvswitch. A limitation in the implementation of userspace packet parsing can allow a malicious user to send a specially crafted packet causing the resulting megaflow in the kernel to be too wide, potentially causing a denial of service. The highest threat from this vulnerability is to system availability.

Vulnerability class: DoS (Denial of Service)

Published 2021-02-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.080 (94.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 94.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.080 · newest: 0.080 · change: 0.000

Affected products

Openvswitch
Debian Linux — versions 9.0, 10.0
Fedoraproject Fedora — versions 33
Openvswitch — versions openvswitch 2.5.12, openvswitch 2.6.10, openvswitch 2.7.13, openvswitch 2.8.11, openvswitch 2.9.9, openvswitch 2.10.7, openvswitch 2.11.6, openvswitch 2.12.3, openvswitch 2.13.3, openvswitch 2.14.2

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

Public proof-of-concept exploits

References

bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
www.openwall.com/lists/oss-security/2021/02/10/4 (Patch, Mailing List, Third Party Advisory)
www.debian.org/security/2021/dsa-4852 (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2021/02/msg00032.html (mailing-list, Mailing List, Third Party Advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
security.gentoo.org/glsa/202311-16 (vendor-advisory)

Frequently asked questions

What is CVE-2020-35498?: CVE-2020-35498 is a high-severity vulnerability in Openvswitch, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2021-02-11.
How severe is CVE-2020-35498?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2020-35498 known to be exploited?: 6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.