What is CVE-2026-43070?

CVE-2026-43070 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Out-of-bounds Read flaw (CWE-125), affecting Linux kernel versions from 6.18.17 onward. CVE-2026-43070 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43070?

CVE-2026-43070 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-43070?

No patch is currently available for CVE-2026-43070. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2026-43070 actively exploited?

CVE-2026-43070 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/125.html

CVE-2026-43070

High

In the Linux kernel, the following vulnerability has been resolved: bpf: Reset register ID for BPF_END value tracking When a register undergoes a BPF_END (byte swap) operation, its scalar value is mutated in-place. If this register previously shared a scalar ID with another register (e.g., after an `r1 = r0` assignment), this tie must be broken. Currently, the verifier misses resetting `dst_reg->id` to 0 for BPF_END. Consequently, if a conditional jump checks the swapped register, the verifier incorrectly propagates the learned bounds to the linked register, leading to false confidence in the linked register's value and potentially allowing out-of-bounds memory accesses. Fix this by explicitly resetting `dst_reg->id` to 0 in the BPF_END case to break the scalar tie, similar to how BPF_NEG handles it via `__mark_reg_known`.

Package Linux Kernel

Published 2026-05-05

Last modified 2026-05-29

CVSS version 3.1

Patch available

Not yet patched

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-125

CVE-2026-43070 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.18.17, 6.19.7 and later are affected. No fixed version recorded yet.

Affected from

≥ 6.18.17 ≥ 6.19.7

References

The following references provide additional information about CVE-2026-43070 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/0d15c3611a2cc5d08993545d4032055ae10ae2c1
Patch
Kernel patch commit
https://git.kernel.org/stable/c/a17443af874229408ce6b78e2c8a2b5adeb4b7d8
Patch
Kernel patch commit
https://git.kernel.org/stable/c/a3125bc01884431d30d731461634c8295b6f0529
Patch

Details

CVE ID CVE-2026-43070

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-05-05

Modified 2026-05-29

KEV No

Patch

Not yet patched

Package linux

Frequently asked questions

What is CVE-2026-43070?

CVE-2026-43070 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 6.18.17 onward . CVE-2026-43070 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43070?

CVE-2026-43070 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-43070?

No patch is currently available for CVE-2026-43070. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2026-43070 actively exploited?

No — CVE-2026-43070 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →