CVE-2026-43341
Description
A flaw was found in the Linux kernel's IPv6 In-situ Operations, Administration, and Maintenance (IOAM6) trace fill functionality. An integer overflow vulnerability exists in the ioam6_fill_trace_data() function, where the schema length calculation can wrap around due to being stored in an 8-bit unsigned integer. This bypasses buffer size checks, leading to a buffer overflow that can result in a denial of service or other memory corruption issues.
Statement
An IPv6 IOAM trace buffer overflow can occur because the schema length contribution is stored in an 8 bit value. With bit 22 enabled and the largest schema payload, sclen wraps from 256 to 0, bypassing the remaining space check while the code still copies the schema header and payload past the trace buffer. The issue is network reachable, although practical exposure is usually limited to IOAM enabled domains or trusted IPv6 networks rather than the public Internet. Impact is kernel memory corruption through an out of bounds write and may cause denial of service or in worst case confidentiality and integrity impact. For the Red Hat Enterprise Linux before 10 is not actual, because not introduced yet (the Fixes patch 8c6f6fa6772696be0c047a711858084b38763728 not applied yet).
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | N/A | 9.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Frequently Asked Questions
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