VulnerabilityPublished 6 May 2026Updated 19 Oct 2026

CVE-2026-43114: Linux kernel · netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 9.4 Critical · fixed in fa4f1f52528c73989d820f32bfca06bec5afeece : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

9.4Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS

0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers can reliably automate steps 1–4 of the kill chain
Technical impact: Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch

Available – fixed in fa4f1f52528c73989d820f32bfca06bec5afeece, f8c39983fc9c1a978c82e6f2df7bfba8a8561587, d3c0037ffe1273fa1961e779ff6906234d6cf53c +5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1, < fa4f1f52528c73989d820f32bfca06bec5afeece	Fixed in fa4f1f52528c73989d820f32bfca06bec5afeece
LinuxLinux	Affected ≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1, < f8c39983fc9c1a978c82e6f2df7bfba8a8561587	Fixed in f8c39983fc9c1a978c82e6f2df7bfba8a8561587
LinuxLinux	Affected ≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1, < d3c0037ffe1273fa1961e779ff6906234d6cf53c	Fixed in d3c0037ffe1273fa1961e779ff6906234d6cf53c
LinuxLinux	Affected ≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1, < c7babe2f28b507e17f28e9f753b7caec72d4857f	Fixed in c7babe2f28b507e17f28e9f753b7caec72d4857f
LinuxLinux	Affected ≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1, < 07de44424bb7f17ef9357e8535df96d9e97c40cb	Fixed in 07de44424bb7f17ef9357e8535df96d9e97c40cb
LinuxLinux	Affected ≥ 7400b063969bdca4a06cd97f1294d765c8eecbe1, < 3d53f9aafd469ae1ea27051e00f5b96ca1b55d52	Fixed in 3d53f9aafd469ae1ea27051e00f5b96ca1b55d52

AI-suggested

A fix for this vulnerability is available in Linux kernel versions after 5.7, as indicated by multiple fixed commit hashes. Users should upgrade to a fixed kernel version that includes these patches. No alternative mitigations or workarounds meeting Red Hat's criteria are currently available. Systems running affected versions should prioritize applying the official kernel updates to remediate this issue.

Description

CVE-2026-43114 is a critical vulnerability in the Linux kernel's netfilter component affecting the nft_set_pipapo_avx2 AVX2 matching functions. The flaw causes incorrect matching behavior when reloading a pipapo set with an 'ipv4 . port' key, leading to erroneous identification of non-matching entries as duplicates. This can result in data integrity issues and unexpected network filtering behavior. The issue is fixed in later kernel versions after 5.7. No known exploits are reported in the wild.

Impact

The vulnerability can cause the netfilter subsystem to misidentify network data entries, potentially resulting in denial of service or data integrity issues in network filtering operations. This may disrupt expected firewall or packet filtering behavior on affected Linux systems using AVX2 instructions for netfilter sets. The impact includes high confidentiality and integrity risks but low availability impact. No active exploitation has been reported.

CWE-480Use of Incorrect Operator (opens in a new tab)
Base weaknessLikelihood of exploit: Low
The product accidentally uses the wrong operator, which changes the logic in security-relevant ways.
CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

Assigned by (CNA): kernel.org (opens in a new tab) · Vendor, Open Source · USA
Reserved: 1 May 2026
CVSS version: 3.1
Vendor Advisory Urls: [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object], [object Object]

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 15:15 UTC

WeaknessesCWE-480, CWE-20

Technical details

References

Community reviews

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