CVE-2026-43114 — netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry New test case fails unexpectedly when avx2 matching functions are used. The test first loads a ranomly generated pipapo set with 'ipv4 . port' key, i.e. nft -f foo. This works. Then, it reloads the set after a flush: (echo flush set t s; cat foo) | nft -f - This is expected to work, because its the same set after all and it was already loaded once. But with avx2, this fails: nft reports a clashing element. The reported clash is of following form: We successfully re-inserted a . b c . d Then we try to insert a . d avx2 finds the already existing a . d, which (due to 'flush set') is marked as invalid in the new generation. It skips the element and moves to next. Due to incorrect masking, the skip-step finds the next matching element *only considering the first field*, i.e. we return the already reinserted "a . b", even though the last field is different and the entry should not have been matched. No such error is reported for the generic c implementation (no avx2) or when the last field has to use the 'nft_pipapo_avx2_lookup_slow' fallback. Bisection points to 7711f4bb4b36 ("netfilter: nft_set_pipapo: fix range overlap detection") but that fix merely uncovers this bug. Before this commit, the wrong element is returned, but erronously reported as a full, identical duplicate. The root-cause is too early return in the avx2 match functions. When we process the last field, we should continue to process data until the entire input size has been consumed to make sure no stale bits remain in the map.
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 0.4% (30-day exploitation probability)+4
- Technical severity (critical)+10
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 — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.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 (Linux Linux, Linux Linux Kernel).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < f8c39983fc9c1a978c82e6f2df7bfba8a8561587version 5.7≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < d3c0037ffe1273fa1961e779ff6906234d6cf53c≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < 0abbc43f71d99baadeeba6fa3fe1c80b676f57ed≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < 07de44424bb7f17ef9357e8535df96d9e97c40cb≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < 3d53f9aafd469ae1ea27051e00f5b96ca1b55d52≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < fa4f1f52528c73989d820f32bfca06bec5afeece≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < 1c43f0dd8691ddf8884793b481ddc7511cf593c3 and 1 more≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1 and < c7babe2f28b507e17f28e9f753b7caec72d4857f |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
≥ 5.7 and < 6.6.136version 7.0-rc5version 7.0-rc4version 7.0-rc3version 7.0-rc2version 7.0-rc1≥ 6.19 and < 6.19.14≥ 6.13 and < 6.18.24 and 1 more≥ 6.7 and < 6.12.83 |
Vulnerable | NIST National Vulnerability Database |
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 |
|---|---|---|---|---|---|
| 9.4 | CVSS 3.1 | Critical | 3.9 | 5.5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 9.4 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 9.4 | CVSS 3.1 | Critical | — | — | Linux via CVE Program (cve.org) e CISA ADP |
| 8.1 | CVSS 3.1 | High | 2.8 | 5.2 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.37%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 9.4
- Source status changed · → Modified
- Record created in this database
- 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 13, 2026 – Oct 13, 2026
References
29 on the record
- git.kernel.org/stable/c/d3c0037ffe1273fa1961e779ff6906234d6cf53c
- git.kernel.org/stable/c/0abbc43f71d99baadeeba6fa3fe1c80b676f57ed
- git.kernel.org/stable/c/fa4f1f52528c73989d820f32bfca06bec5afeece
- git.kernel.org/stable/c/3d53f9aafd469ae1ea27051e00f5b96ca1b55d52
- git.kernel.org/stable/c/07de44424bb7f17ef9357e8535df96d9e97c40cb
- access.redhat.com/errata/RHSA-2026:62642
- access.redhat.com/errata/RHSA-2026:62639
- access.redhat.com/errata/RHSA-2026:59723
- github.com/advisories/GHSA-6cwp-88hv-x237
- access.redhat.com/errata/RHSA-2026:64767
- access.redhat.com/errata/RHSA-2026:65712
- git.kernel.org/stable/c/c7babe2f28b507e17f28e9f753b7caec72d4857f
- access.redhat.com/errata/RHSA-2026:62640
- access.redhat.com/errata/RHSA-2026:67721
- cert-portal.siemens.com/productcert/html/ssa-784472.html
- git.kernel.org/stable/c/f8c39983fc9c1a978c82e6f2df7bfba8a8561587
- nvd.nist.gov/vuln/detail/CVE-2026-43114
- access.redhat.com/errata/RHSA-2026:67723
- access.redhat.com/errata/RHSA-2026:62641
- access.redhat.com/security/cve/CVE-2026-43114
- access.redhat.com/errata/RHSA-2026:62568
- access.redhat.com/errata/RHSA-2026:66351
- git.kernel.org/stable/c/1c43f0dd8691ddf8884793b481ddc7511cf593c3
- access.redhat.com/errata/RHSA-2026:66376
- bugzilla.redhat.com/show_bug.cgi
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43114.json
- access.redhat.com/errata/RHSA-2026:66370
- access.redhat.com/errata/RHSA-2026:63093
- access.redhat.com/errata/RHSA-2026:62638
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 1d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 1d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 2d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 2d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 2d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 2d
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-2026-43114 is "netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry", rated Critical. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.4 describes technical severity. EPSS 0.37% 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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