CVE-2026-98794 json
ipvs: filter some flags received in the backup server
published 24d ago modified 12d ago also EUVD-2026-103879
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 12%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
ipvs: filter some flags received in the backup server
While the IPVS SYNC protocol is not secure by design we can still protect the backup server from messages that can wreak havoc.
This commit addresses problems from received connection flags or their combinations. We now drop messages as follows:
1. the NO_CPORT+TEMPLATE combination allows lookups for normal connections to hit template which can break in many ways. While the master does not sync connections with NO_CPORT flag, i.e. before they are established, we still accept NO_CPORT without TEMPLATE.
2. ONE_PACKET: it is not sent by master, so we do not expect it in backup. Before now it was ignored by IP_VS_CONN_F_BACKUP_MASK for protocol v1 while protocol v0 created connections that are not hashed and dropped immediately. Better to apply the IP_VS_CONN_F_BACKUP_MASK also to the flags from v0 messages for consistency with v1.
Patch / fix
- Linux Linux 7.3
- linux Debian 13 6.12.113-1
- linux Debian 14 7.2.10-1
- linux-6.12 Debian 12 6.12.113-1~deb12u1
debian advisories DEBIAN-CVE-2026-98794
- linux Ubuntu 24.04 LTS 6.8.0-149.149
- linux Ubuntu 26.04 LTS 7.0.0-43.43
- linux-aws Ubuntu 24.04 LTS 6.8.0-1069.74
- linux-aws Ubuntu 26.04 LTS 7.0.0-1017.18
- linux-gcp Ubuntu 24.04 LTS 6.8.0-1073.81
- linux-gcp Ubuntu 26.04 LTS 7.0.0-1017.19
- linux-gke Ubuntu 24.04 LTS 6.8.0-1068.77
- linux-gke Ubuntu 26.04 LTS 7.0.0-1010.11
ubuntu advisories UBUNTU-CVE-2026-98794
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- kernel Azure Linux 3.0 6.6.161.1-1
azure linux advisories AZL-108878
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- git.kernel.org/stable/c/ef3cd6c0b826e50dc21653b32552e258de6fd51c commit
- git.kernel.org/stable/c/3a9f5459db60311643bfbadf019f6d5370f2f26a commit
- git.kernel.org/stable/c/438a5335276614186d6a96b8e7bddce811ad4ad6 commit
- git.kernel.org/stable/c/d7d33c9efa9d1a2f244a1a64ec9b540b0f8975a0 commit
- git.kernel.org/stable/c/f4cd1db7d421e82945713a36084bb0c35b75b27e commit
- git.kernel.org/stable/c/55d033324f67a15ff56be6d38d6e87f644e0ed62 commit
- git.kernel.org/stable/c/45a93111835ccfea7d969ec73588e33745fd9834 commit
- git.kernel.org/stable/c/f96e91748f6304668fe647e686d199d7207d36f1 commit
Is CVE-2026-98794 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerVendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-98794 updated cvss 6.5
kernel: ipvs: filter some flags received in the backup server
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 moreaffected: no fix planned “Out of support scope”
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Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9affected: no fix available “Fix deferred”
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
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-11).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/ef3cd6c0b826e50dc21653b32552e258de6fd51c
- git.kernel.org /stable/c/3a9f5459db60311643bfbadf019f6d5370f2f26a
- git.kernel.org /stable/c/438a5335276614186d6a96b8e7bddce811ad4ad6
- git.kernel.org /stable/c/d7d33c9efa9d1a2f244a1a64ec9b540b0f8975a0
- git.kernel.org /stable/c/f4cd1db7d421e82945713a36084bb0c35b75b27e
- git.kernel.org /stable/c/55d033324f67a15ff56be6d38d6e87f644e0ed62
- git.kernel.org /stable/c/45a93111835ccfea7d969ec73588e33745fd9834
- git.kernel.org /stable/c/f96e91748f6304668fe647e686d199d7207d36f1
Sources
- CVE List CVE-2026-98794
- NVD CVE-2026-98794
Fencer Intel 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.