# CVE-2026-43030: Linux Kernel BPF verifier incorrect state pruning in regsafe

Source: https://junglewise.ai/threats/cve-2026-43030-linux-kernel-bpf-verifier-incorrect-state-pruning-in-regsafe  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-01. Updated: 2026-07-14  
License: CC BY 4.0 with a link back

CVE-2026-43030 · Severity: high · CVSS 7.8 · Published 2026-05-01

A vulnerability was identified in the Linux kernel's BPF verifier, a component responsible for ensuring that custom network and system programs run safely without crashing the operating system. Due to a logic error, the verifier might incorrectly approve a program that performs unsafe memory operations on network packets. If exploited, a local attacker could potentially gain unauthorized access to sensitive data or cause a complete system crash, impacting the reliability and security of the affected device.

Technologies: [Linux Kernel](https://junglewise.ai/threats/technologies/kernel), [Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP](https://junglewise.ai/threats/technologies/simatic-s7-1500-cpu-1518-4-pn-dp-mfp), [Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP](https://junglewise.ai/threats/technologies/simatic-s7-1500-cpu-1518f-4-pn-dp-mfp), [Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP](https://junglewise.ai/threats/technologies/siplus-s7-1500-cpu-1518-4-pn-dp-mfp). Vendors: [Linux](https://junglewise.ai/threats/vendors/linux), [Siemens](https://junglewise.ai/threats/vendors/siemens).

## Quick answers

**Is CVE-2026-43030 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-43030 being exploited in the wild.

**How severe is CVE-2026-43030?** High severity, with a CVSS score of 7.8, published 1 May 2026.

**Which products and versions are affected?** Linux Kernel 6d94e741a8ff to fixed versions; Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5, V3.1.6; Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5, V3.1.6; Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5, V3.1.6.

**Is there a fix for CVE-2026-43030?** A patch was published on 2026-04-11: Commits merged into various stable kernel branches Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-43030 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-43030?** Check whether you run Linux Kernel, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A vulnerability exists in the Linux kernel BPF verifier within the regsafe() function in kernel/bpf/verifier.c. The issue arises when comparing register states for packet pointers; specifically, if an old register state has a range marked as BEYOND_PKT_END while the current state has a different range, regsafe() may incorrectly return true. This causes the verifier to skip exploration of valid packet ranges, leading to incorrect state pruning. A local attacker with the ability to load BPF programs could exploit this to bypass verifier safety checks, potentially achieving arbitrary kernel memory access or a denial-of-service condition. The fix introduces explicit checks for special packet end markers to ensure states are not incorrectly considered equivalent.

## Affected products

- Linux Linux Kernel 6d94e741a8ff to fixed versions
- Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5, V3.1.6
- Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5, V3.1.6
- Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5, V3.1.6

## Timeline

- 2026-03-31: disclosed: Initial patch submitted by Alexei Starovoitov
- 2026-04-11: patched: Commits merged into various stable kernel branches
- 2026-05-01: advisory: CVE published

## References

- [https://git.kernel.org/stable/c/015a74476dc1ab6923d89f1ee009aaf43faa7185](https://git.kernel.org/stable/c/015a74476dc1ab6923d89f1ee009aaf43faa7185)
- [https://git.kernel.org/stable/c/37db6b9726d0bcf91cbdf9d63b558c50da49f968](https://git.kernel.org/stable/c/37db6b9726d0bcf91cbdf9d63b558c50da49f968)
- [https://git.kernel.org/stable/c/7241da033fdc507b920e092dab1f97b945cb0370](https://git.kernel.org/stable/c/7241da033fdc507b920e092dab1f97b945cb0370)
- [https://git.kernel.org/stable/c/8aebe18069394f4a79d2d82080a0f806da449996](https://git.kernel.org/stable/c/8aebe18069394f4a79d2d82080a0f806da449996)
- [https://git.kernel.org/stable/c/a8502a79e832b861e99218cbd2d8f4312d62e225](https://git.kernel.org/stable/c/a8502a79e832b861e99218cbd2d8f4312d62e225)
- [https://git.kernel.org/stable/c/b52f6d0ef7b308f9d05bbddb78749852f28e8e40](https://git.kernel.org/stable/c/b52f6d0ef7b308f9d05bbddb78749852f28e8e40)
- [https://git.kernel.org/stable/c/b99d82706bd1511bb875e3de7154698fd9215c99](https://git.kernel.org/stable/c/b99d82706bd1511bb875e3de7154698fd9215c99)

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