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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | openvswitch | 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 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openvswitch | 2.15.0~git20210104.def6eb1ea+dfsg1-5 | — |
| Debian 13 | openvswitch | 2.15.0~git20210104.def6eb1ea+dfsg1-5 | — |
| Debian 12 | openvswitch | 2.15.0~git20210104.def6eb1ea+dfsg1-5 | — |
| Debian 10 | openvswitch | 2.10.7+ds1-0+deb10u1 | DSA-4852-1 |
| Debian 9 | openvswitch | 2.6.10-0+deb9u1 | DLA-2571-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | openvswitch | 2.13.1-0ubuntu0.20.04.4 | USN-4729-1 |
| Ubuntu 18.04 LTS | openvswitch | 2.9.8-0ubuntu0.18.04.2 | USN-4729-1 |
| Ubuntu 16.04 LTS | openvswitch | 2.5.9-0ubuntu0.16.04.3 | USN-4729-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | openvswitch2.11 +4 | 2.11.3-83.el8fdp | RHSA-2021:0837 |
| RHEL 8 | openvswitch2.13 +5 | 2.13.0-79.5.el8fdp | RHSA-2021:0497 |
| RHEL 7 | openvswitch +3 | 2.9.9-1.el7fdp | RHSA-2021:2077 |
| RHEL 7 | openvswitch2.11 +3 | 2.11.3-86.el7fdp | RHSA-2021:1050, RHSA-2021:0834 |
| RHEL 7 | openvswitch2.13 +4 | 2.13.0-81.el7fdp | RHSA-2021:0835 |
| RHEL 7 | ovn2.11 +2 | 2.11.1-57.el7fdp | RHSA-2021:1050 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat OpenStack 13 | openvswitch2.11 +3 | 2.11.3-86.el7fdp | RHSA-2021:2456 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1, SUSE-SU-2021:0436-1 |
| SLES 15 SP1 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1 |
| SLES 15 | openvswitch | 2.11.5-6.33.3 | SUSE-SU-2021:0440-1 |
| SLES 12 SP5 | openvswitch | 2.11.5-3.9.1 | SUSE-SU-2022:3384-1 |
| SLES 12 SP4 | openvswitch | 2.8.10-4.26.1 | SUSE-SU-2021:0479-1 |
Show 21 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | openvswitch | 2.7.12-3.39.1 | SUSE-SU-2021:0446-1 |
| SLES 12 SP2 | openvswitch +1 | 2.5.11-25.29.1 | SUSE-SU-2021:0451-1 |
| SLES for SAP 15 SP1 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1 |
| SLES for SAP 15 | openvswitch | 2.11.5-6.33.3 | SUSE-SU-2021:0440-1 |
| SLES for SAP 12 SP5 | openvswitch | 2.11.5-3.9.1 | SUSE-SU-2022:3384-1 |
| SLES for SAP 12 SP4 | openvswitch | 2.8.10-4.26.1 | SUSE-SU-2021:0479-1 |
| SLES for SAP 12 SP3 | openvswitch | 2.7.12-3.39.1 | SUSE-SU-2021:0446-1 |
| SLES for SAP 12 SP2 | openvswitch +1 | 2.5.11-25.29.1 | SUSE-SU-2021:0451-1 |
| SLE HPC 15 SP1 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1 |
| SLE HPC 15 | openvswitch | 2.11.5-6.33.3 | SUSE-SU-2021:0440-1 |
| SUSE OpenStack Cloud Crowbar 9 | openvswitch | 2.8.10-4.26.1 | SUSE-SU-2021:0479-1 |
| SUSE OpenStack Cloud Crowbar 8 | openvswitch | 2.7.12-3.39.1 | SUSE-SU-2021:0446-1 |
| SUSE OpenStack Cloud 9 | openvswitch | 2.8.10-4.26.1 | SUSE-SU-2021:0479-1 |
| SUSE OpenStack Cloud 8 | openvswitch | 2.7.12-3.39.1 | SUSE-SU-2021:0446-1 |
| SUSE OpenStack Cloud 7 | openvswitch +1 | 2.5.11-25.29.1 | SUSE-SU-2021:0451-1 |
| SUSE Manager Server 4.0 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1 |
| SUSE Manager Retail Branch Server 4.0 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1 |
| SUSE Manager Proxy 4.0 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1 |
| SUSE HPE Helion OpenStack 8 | openvswitch | 2.7.12-3.39.1 | SUSE-SU-2021:0446-1 |
| SUSE Enterprise Storage 6 | openvswitch | 2.11.5-3.15.3 | SUSE-SU-2021:0439-1 |
| SUSE Enterprise Storage 5 | openvswitch | 2.7.12-3.39.1 | SUSE-SU-2021:0446-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.2 | openvswitch | 2.13.2-lp152.3.12.1 | openSUSE-SU-2021:0283-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.23 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.22 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.21 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.20 | openvswitch | 2.12.3-r0 | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.18 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.17 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.16 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.15 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.14 | openvswitch | 2.12.3-r0 | — |
| Alpine v3.13 | openvswitch | 2.12.3-r0 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
freddierice/cve-2020-35498-flag ★ 0 · Feb 12, 2021
Flag the cve-2020-35498 attack
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 19
- RHSA-2021:2456 Red Hat Security Advisory: Red Hat OpenStack Platform 13.0 (openvswitch2.11) security update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2021:2077 Red Hat Security Advisory: openvswitch security update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2021:1050 Red Hat Security Advisory: openvswitch2.11 security update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2021:0837 Red Hat Security Advisory: openvswitch2.11 security update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2021:0835 Red Hat Security Advisory: openvswitch2.13 security update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2021:0834 Red Hat Security Advisory: openvswitch2.11 security update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2021:0497 Red Hat Security Advisory: openvswitch2.13 security and bug fix update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- DSA-4852-1 openvswitch - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2571-1 openvswitch - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-4729-1 openvswitch vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2021:0440-1 Security update for openvswitch SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0283-1 Security update for openvswitch SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0436-1 Security update for openvswitch SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0479-1 Security update for openvswitch SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0451-1 Security update for openvswitch SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:3384-1 Security update for openvswitch SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0446-1 Security update for openvswitch SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0439-1 Security update for openvswitch SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2023-0916 Red Hat Enterprise Linux: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 11, 2024
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1908845
- https://www.openwall.com/lists/oss-security/2021/02/10/4
- DSA-4852 vendor-advisory
- [debian-lts-announce] 20210219 [SECURITY] [DLA 2571-1] openvswitch security update mailing-list
- FEDORA-2021-fba11d37ee vendor-advisory
- GLSA-202311-16 vendor-advisory