CVE-2026-43453
Description
A flaw was found in the Linux kernel's netfilter component, specifically within the nft_set_pipapo module. The pipapo_drop() function performs a stack out-of-bounds read. This occurs when an argument is evaluated at the call site before the function body executes, leading to a read beyond the allocated rulemap array. This could potentially lead to information disclosure or system instability.
Statement
pipapo_drop() can read one element past the stack allocated rulemap array when processing the last pipapo field. The out of bounds value is evaluated as a function argument even though pipapo_unmap() would return early for the last field, which makes this a real stack OOB read confirmed by KASAN. For the CVSS the PR:L is used in the paranoid score because some systems delegate CAP_NET_ADMIN through namespaces or containers, although normal nftables rule management is administrator controlled. The issue is not network reachable and is triggered through local nftables set update or removal control plane operations rather than packet traffic. Impact is mainly low availability through KASAN or kernel fault on instrumented or hardened builds. Limited confidentiality is only a paranoid consideration because the primitive is a stack OOB read, but the patch context does not show a reliable data disclosure path, OOB write, UAF, arbitrary write, or privilege escalation.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.1 | 7.1 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | High | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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