CVE-2026-97417
Description
A flaw was found in the Linux kernel's netfilter connection tracking subsystem. The TCP option processing mechanism improperly assumes memory alignment when reading packet headers. A remote attacker could exploit this vulnerability by sending crafted TCP packets with misaligned SACK options through a system running conntrack (e.g., Linux firewall/NAT using iptables/nftables), causing a memory access fault that leads to a kernel panic and Denial of Service (DoS).
Mitigation
Systems that do not require stateful firewall, NAT, or connection tracking can eliminate exposure by unloading the nf_conntrack kernel module. On systems where conntrack is required, exposure can be reduced by applying NOTRACK rules in the raw table to bypass connection tracking on untrusted or internet-facing interfaces, ensuring the vulnerable TCP SACK parsing code path in tcp_sack() is not reached for attacker-controlled traffic.
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 | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability,Integrity,Confidentiality
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart
When a memory buffer is accessed using the wrong type, it could read or write memory out of the bounds of the buffer, if the allocated buffer is smaller than the type that the code is attempting to access, leading to a crash and possibly code execution.
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