# CVE-2026-43070: linux: In the Linux kernel, the following vulnerability has been resolved:  bpf: Reset register ID for BPF_END value trackin...

CVE-2026-43070 is fixed in linux on 1 platform by DEBIAN-CVE-2026-43070 (version 6.19.11-1), released May 15, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-43070
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0012
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 5, 2026

## Description

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`.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 6.19.11-1 | [DEBIAN-CVE-2026-43070](https://patchblox.com/security/data/fix/linux/debian-cve-2026-43070.md) | May 15, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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