# CVE-2026-45843: slip: bound decode() reads against the compressed packet length

> A missing bounds check in the Linux kernel's SLIP driver allows attackers to read memory beyond packet boundaries, potentially disclosing sensitive kernel data.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-88553, BELL-CVE-2026-45843, DEBIAN-CVE-2026-45843, GHSA-58qm-9wwf-x958, ROOT-OS-DEBIAN-11-CVE-2026-45843, ROOT-OS-DEBIAN-12-CVE-2026-45843, ROOT-OS-DEBIAN-13-CVE-2026-45843, ROOT-OS-UBUNTU-2204-CVE-2026-45843, ROOT-OS-UBUNTU-2404-CVE-2026-45843, UBUNTU-CVE-2026-45843

## What is CVE-2026-45843?

CVE-2026-45843 is a high-severity vulnerability in Linux kernel, published on 27 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

slip: bound decode() reads against the compressed packet length

slhc_uncompress() parses a VJ-compressed TCP header by advancing a
pointer through the packet via decode() and pull16(). Neither helper
bounds-checks against isize, and decode() masks its return with
& 0xffff so it can never return the -1 that callers test for -- those
error paths are dead code.

A short compressed frame whose change byte requests optional fields
lets decode() read past the end of the packet. The over-read bytes
are folded into the cached cstate and reflected into subsequent
reconstructed packets.

Make decode() and pull16() take the packet end pointer and return -1
when exhausted. Add a bounds check before the TCP-checksum read.
The existing == -1 tests now do what they were always meant to.

Weakness: CWE-126 (Buffer Over-read)

## Which versions are affected by CVE-2026-45843?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-45843?

Apply the vendor's patch.

## Is CVE-2026-45843 being exploited?

There is no known exploitation of CVE-2026-45843 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45843 and fix it if it is affected.

What it is: CVE-2026-45843 is a high-severity vulnerability in Linux kernel, published on 27 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45843 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45843/ (Markdown: https://insights.sbomify.com/CVE-2026-45843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45843
- OSV: https://osv.dev/vulnerability/CVE-2026-45843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45843/
Summaries are generated and may contain mistakes; the official description above is the record.