netfilter: xt_CT: drop pending enqueued packets on template removal
Published Mar 25, 2026
7.8
HIGHCVSS 3.1
EPSS 0.13%
Description
Templates refer to objects that can go away while packets are sitting in nfqueue refer to:
- helper, this can be an issue on module removal. - timeout policy, nfnetlink_cttimeout might remove it.
The use of templates with zone and event cache filter are safe, since this just copies values.
Flush these enqueued packets in case the template rule gets removed.
Affected products
-
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version
-
- Version 3.4StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<3.4
- Version 5.10.253StatusunaffectedConstraints<=5.10.*
- Version 5.15.203StatusunaffectedConstraints<=5.15.*
- Version 6.1.167StatusunaffectedConstraints<=6.1.*
- Version 6.12.78StatusunaffectedConstraints<=6.12.*
- Version 6.18.20StatusunaffectedConstraints<=6.18.*
- Version 6.19.10StatusunaffectedConstraints<=6.19.*
- Version 6.6.130StatusunaffectedConstraints<=6.6.*
- Version 7.0StatusunaffectedConstraints<=*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
| |||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
- ≥ 3.4.1 · < 5.10.253
- ≥ 5.11 · < 5.15.203
- ≥ 5.16 · < 6.1.167
- ≥ 6.2 · < 6.6.130
- ≥ 6.7 · < 6.12.78
- ≥ 6.13 · < 6.18.20
- ≥ 6.19 · < 6.19.10
- 3.4
- 7.0
- 7.0
- 7.0
- 7.0
- 7.0
- 7.0
- 7.0
No data.
Red Hat Enterprise Linux 10
kernel
Fix deferred
Red Hat Enterprise Linux 6
kernel
Out of support scope
Red Hat Enterprise Linux 7
kernel
Fix deferred
Red Hat Enterprise Linux 7
kernel-rt
Fix deferred
Red Hat Enterprise Linux 8
kernel
Fix deferred
Red Hat Enterprise Linux 8
kernel-rt
Fix deferred
Red Hat Enterprise Linux 9
kernel
Fix deferred
Red Hat Enterprise Linux 9
kernel-rt
Fix deferred
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This flaw affects systems using nfqueue with connection tracking templates. When templates referencing helpers or timeout policies are removed while packets are queued, those packets can reference freed objects. The issue occurs during module removal or timeout policy deletion while traffic is being processed via nfqueue.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Mar–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.13% (0.00128) | 2.10th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.12% (0.00123) | 2.40th | v5 (v2026.06.15) |
| Mar 25, 2026 | 0.02% (0.00024) | 6.53th | v4 (v2025.03.14) |
References (15)
- https://access.redhat.com/security/cve/CVE-2026-23391 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2451269 Issue Tracking
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://git.kernel.org/stable/c/19a230dec6bb8928e3f96387f9085cf2c79bcef9 Patch
- https://git.kernel.org/stable/c/55445134d42b84cb0a272e42c98d233ca65eca83 Patch
- https://git.kernel.org/stable/c/63b8097cea1923fe82cd598068d0796da8c015ec Patch
- https://git.kernel.org/stable/c/777d02efe3d630cca4c1b63962cec17c57711325 Patch
- https://git.kernel.org/stable/c/cb549925875fa06dd155e49db4ac2c5044c30f9c Patch
- https://git.kernel.org/stable/c/cc57506dd66555899560b9c0f24e813f034e12ec Patch
- https://git.kernel.org/stable/c/d2d0bae0c9a2a17b6990a2966f5cdce0813d6256 Patch
- https://git.kernel.org/stable/c/f62a218a946b19bb59abdd5361da85fa4606b96b Patch
- https://lore.kernel.org/linux-cve-announce/2026032548-CVE-2026-23391-bb43@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2026-23391
- https://www.cve.org/CVERecord?id=CVE-2026-23391
Change history (0)
No recorded changes yet.