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Public proof of conceptFix available

CVE-2020-35498

A public proof of concept exists; no exploitation attested.

  • Published2021-02-11
  • Fixed in2.14.2 · 2.13.3 · 2.12.3 · 2.11.6 · 2.10.7 · 2.9.9
  • WeaknessCWE-400

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2021-02-1118:15CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-35498?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-35498?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Openvswitch
BranchAffectedFixed in
2.14≥ 2.14.0, < 2.14.22.14.2
2.13≥ 2.13.0, < 2.13.32.13.3
2.12≥ 2.12.0, < 2.12.32.12.3
2.11≥ 2.11.0, < 2.11.62.11.6
2.10≥ 2.10.0, < 2.10.72.10.7
2.9≥ 2.9.0, < 2.9.92.9.9
2.8≥ 2.8.0, < 2.8.112.8.11
2.7≥ 2.7.0, < 2.7.132.7.13
2.6≥ 2.6.0, < 2.6.102.6.10
2.5≥ 2.5.0, < 2.5.122.5.12
Debian debian linux
BranchAffectedFixed in
9.0= 9.0no fix published
10.0= 10.0no fix published
Fedoraproject fedora
BranchAffectedFixed in
33.x= 33no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Openvswitch to 2.14.2 · 2.13.3 · 2.12.3 · 2.11.6 · 2.10.7 · 2.9.9 · 2.8.11 · 2.7.13

Advisories and patches

Detection

read 2026-10-23 19:23 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedfreddierice/cve-2020-35498-flag
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2021-02-11
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is 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.

Is CVE-2020-35498 actively exploited?

Active exploitation of CVE-2020-35498 has not been confirmed. Its EPSS score was 8.0% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-35498?

CVE-2020-35498 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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