# CVE-2026-98777: binder: fix leaked fd fixups on TF_UPDATE_TXN supersede

> A local attacker can trigger a memory leak in the Linux kernel binder driver, leading to file descriptor exhaustion and denial of service.

- **Severity:** Not scored
- **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:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-108683, BELL-CVE-2026-98777, DEBIAN-CVE-2026-98777, GHSA-crhv-x2gr-r2gm, UBUNTU-CVE-2026-98777

## What is CVE-2026-98777?

CVE-2026-98777 is a memory corruption vulnerability in Linux, published on 18 Oct 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:

binder: fix leaked fd fixups on TF_UPDATE_TXN supersede

When a TF_UPDATE_TXN transaction supersedes a pending async transaction
in a frozen process, the outdated transaction is freed with kfree()
directly. This skips binder_free_txn_fixups(), leaking all
binder_txn_fd_fixup entries and their fget()'d struct file references.

The leaked file refcounts never reach zero, so the struct file objects
are permanently pinned in memory. They survive process exit and
accumulate across invocations until file-max exhaustion.

Every other transaction cleanup path (binder_free_transaction(),
binder_transaction() error paths, binder_release_work()) correctly
calls binder_free_txn_fixups(). Add the missing call before kfree()
in the t_outdated cleanup block.

## Which versions are affected by CVE-2026-98777?


## How do I fix CVE-2026-98777?

Apply the vendor's patch.

## Is CVE-2026-98777 being exploited?

There is no known exploitation of CVE-2026-98777 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98777 and fix it if it is affected.

What it is: CVE-2026-98777 is a memory corruption vulnerability in Linux, published on 18 Oct 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-2026-98777 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-2026-98777/ (Markdown: https://insights.sbomify.com/CVE-2026-98777/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98777
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98777
- OSV: https://osv.dev/vulnerability/CVE-2026-98777

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98777/
Summaries are generated and may contain mistakes; the official description above is the record.