# CVE-2026-98969: net/sched: em_text: reject unterminated algo before autoload


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** AZL-110789, BELL-CVE-2026-98969, DEBIAN-CVE-2026-98969, GHSA-g75r-rwjf-jp26, UBUNTU-CVE-2026-98969

## What is CVE-2026-98969?

CVE-2026-98969 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

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

net/sched: em_text: reject unterminated algo before autoload

This is a follow-up to commit 9c572a83037a ("net/sched: fix potential
stack infoleak in em_text_dump()"), which zero-initialised the dump-side
struct. Sashiko pointed at a pre-existing bug that exposed the change-side
input-validation gap open.

em_text_change() casts the raw netlink attribute payload to struct
tcf_em_text and passes conf->algo, a 16-byte array with no enforced NUL
terminator, to textsearch_prepare().  On the TS_AUTOLOAD retry
textsearch_prepare() calls request_module("ts_%s", algo); vsnprintf()
walks %s until it finds a NUL, so an algo[] with no NUL reads past the
array into the adjacent struct fields and payload and feeds those bytes
to the usermode helper command line.  This is an out-of-bounds read and
a kernel memory disclosure.

Reject the attribute when no NUL exists within TC_EM_TEXT_ALGOSIZ bytes,
matching the check xt_string has had since 3ab720881b6e.

Conditions to recreate the bug:
- CAP_NET_ADMIN on the target netns (namespace-local via unshare -Urn
  is enough)
- install clsact on an interface, then add a basic filter with one text
  ematch whose algo[] is 16 bytes with no NUL (e.g. "A"*16) and
  pattern_len at least 1
- the add fails with -ENOENT and the kernel invokes modprobe with a
  module name made of "ts_" plus the 16 bytes and the adjacent payload

## Which versions are affected by CVE-2026-98969?


## How do I fix CVE-2026-98969?

Upgrade to a fixed version.

## Is CVE-2026-98969 being exploited?

There is no known exploitation of CVE-2026-98969 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98969 and fix it if it is affected.

What it is: CVE-2026-98969 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98969 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-2026-98969/ (Markdown: https://insights.sbomify.com/CVE-2026-98969/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98969
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98969
- OSV: https://osv.dev/vulnerability/CVE-2026-98969

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98969/
Summaries are generated and may contain mistakes; the official description above is the record.