CVE-2023-4004 — Kernel: netfilter: use-after-free due to improper element removal in nft_pipapo_remove()
A use-after-free flaw was found in the Linux kernel's netfilter in the way a user triggers the nft_pipapo_remove function with the element, without a NFT_SET_EXT_KEY_END. This issue could allow a local user to crash the system or potentially escalate their privileges on the system.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.9% (30-day exploitation probability)+9
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — patchwork.ozlabs.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Fedoraproject Fedora, Linux Linux Kernel…).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 10.0version 11.0version 12.0 | Vulnerable | NIST National Vulnerability Database |
| Fedoraproject | Fedora | version 38 | Vulnerable | NIST National Vulnerability Database |
| Linux | Linux Kernel | ≥ 5.6 and < 5.10.188≥ 5.11 and < 5.15.123≥ 5.16 and < 6.1.42≥ 6.2 and < 6.4.7 | Vulnerable | NIST National Vulnerability Database |
| Netapp | H300s | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H410s | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H500s | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H700s | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux | version 9.0version 8.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Red Hat Enterprise Linux 8 | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 8.2 Advanced Update Support | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 8.2 Telecommunications Update Service | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 8.4 Telecommunications Update Service | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 9 | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 9.0 Extended Update Support | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | secalert@redhat.com via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | redhat via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · red hat/red hat enterprise linux 8, red hat/red hat enterprise linux 8.2 advanced update support, red hat/red hat enterp
- Record published
- Fix documented
- Affected products added · linux/linux kernel, fedoraproject/fedora, redhat/enterprise linux, netapp/h300s, netapp/h410s, netapp/h500s, netapp/h700
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- 2023
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
32 on the record
- patchwork.ozlabs.org/project/netfilter-devel/patch/20230719190824.21196-1-fw@strlen.de/
- access.redhat.com/errata/RHSA-2023:5548
- github.com/advisories/GHSA-h3j8-wx8r-29j6
- nvd.nist.gov/vuln/detail/CVE-2023-4004
- access.redhat.com/errata/RHSA-2023:7434
- access.redhat.com/errata/RHSA-2023:5091
- cert-portal.siemens.com/productcert/html/ssa-794697.html
- security.netapp.com/advisory/ntap-20231027-0001/
- access.redhat.com/errata/RHSA-2023:7411
- access.redhat.com/errata/RHSA-2023:7382
- access.redhat.com/errata/RHSA-2023:4967
- www.debian.org/security/2023/dsa-5492
- access.redhat.com/errata/RHSA-2023:5627
- packetstormsecurity.com/files/175072/Kernel-Live-Patch-Security-Notice-LSN-0098-1.html
- www.debian.org/security/2023/dsa-5480
- access.redhat.com/errata/RHSA-2023:4962
- cert-portal.siemens.com/productcert/html/ssa-831302.html
- access.redhat.com/security/cve/CVE-2023-4004
- access.redhat.com/errata/RHSA-2023:5221
- access.redhat.com/errata/RHSA-2023:7417
- packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html
- access.redhat.com/errata/RHSA-2023:5244
- security.netapp.com/advisory/ntap-20231027-0001
- access.redhat.com/errata/RHSA-2023:5093
- access.redhat.com/errata/RHSA-2023:7431
- access.redhat.com/errata/RHSA-2023:7389
- lists.debian.org/debian-lts-announce/2023/10/msg00027.html
- access.redhat.com/errata/RHSA-2023:5069
- access.redhat.com/errata/RHSA-2023:4961
- bugzilla.redhat.com/show_bug.cgi
- patchwork.ozlabs.org/project/netfilter-devel/patch/20230719190824.21196-1-fw@strlen.de
- access.redhat.com/errata/RHSA-2023:5255
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-110927 Openssh: openssh: a compressed payload can expand past the maximum packet size 8h
- Medium CVE-2026-110924 Openssh: openssh: gssapi delegated credentials can be stored after a failed authentication 8h
- Medium CVE-2026-110926 Openssh: openssh: shared lz77 compression dictionary leaks plaintext across channels 16h
- Medium CVE-2026-110925 Openssh: openssh: '$' and '\' in a command-line username expand through %u 16h
- Medium CVE-2026-110923 Openssh: openssh: sftp can write outside the destination directory from a server-supplied path 16h
- Medium CVE-2026-86856 Dpdk: dpdk: stack and heap buffer overflow in nfp vdpa driver 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2023-4004 is "Kernel: netfilter: use-after-free due to improper element removal in nft_pipapo_remove()", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.92% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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