# CVE-2026-93111: bpf: Mark tracing_multi trampolines as ftrace managed

> A missing flag in Linux kernel BPF tracing causes a kernel warning and potential instability when releasing links, requiring a patch to fix.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** GHSA-285f-2chv-p9fq, UBUNTU-CVE-2026-93111

## What is CVE-2026-93111?

CVE-2026-93111 is a high-severity denial of service vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

bpf: Mark tracing_multi trampolines as ftrace managed

Since tracing_multi link does not set ftrace_managed, it would fail to
release the tracing_multi link when attaching tracing_multi link and
then attaching fentry link.

[    3.714215] WARNING: kernel/bpf/trampoline.c:1727 at bpf_trampoline_multi_detach+0x20b/0x240, CPU#1: test_progs/97
...
[    3.733170]  bpf_tracing_multi_link_release+0x14/0x30
[    3.733890]  bpf_link_free+0x58/0x130
[    3.734414]  bpf_link_release+0x23/0x30

Fix it by setting 'ftrace_managed = true' in register_fentry_multi().

## Which versions are affected by CVE-2026-93111?


## How do I fix CVE-2026-93111?

Apply the vendor's patch.

## Is CVE-2026-93111 being exploited?

There is no known exploitation of CVE-2026-93111 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93111 and fix it if it is affected.

What it is: CVE-2026-93111 is a high-severity denial of service vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-93111 in the wild and no public exploit code.

Affected product: Linux. 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-2026-93111/ (Markdown: https://insights.sbomify.com/CVE-2026-93111/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93111
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93111
- OSV: https://osv.dev/vulnerability/CVE-2026-93111

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93111/
Summaries are generated and may contain mistakes; the official description above is the record.