# CVE-2026-89608: ecryptfs: pass packet set buffer size to parser

> A buffer size miscalculation in the ecryptfs kernel module can lead to memory corruption, potentially allowing attackers to cause denial of service or execute arbitrary code.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-100184, BELL-CVE-2026-89608, DEBIAN-CVE-2026-89608, GHSA-m87w-w8mv-rf6c, UBUNTU-CVE-2026-89608

## What is CVE-2026-89608?

CVE-2026-89608 is a high-severity vulnerability in Linux, published on 11 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:

ecryptfs: pass packet set buffer size to parser

ecryptfs_parse_packet_set() receives a pointer into the file header, but
it calculates the remaining packet buffer size from PAGE_SIZE - 8.  For
version 1 headers the packet set starts later in the header, so this can
overstate the available buffer.

Pass the actual packet set buffer length from the caller and calculate
per-packet limits from the remaining bytes in that buffer.  Recompute the
remaining length after consuming a tag 3 packet before parsing the
following tag 11 packet.

## Which versions are affected by CVE-2026-89608?


## How do I fix CVE-2026-89608?

Apply the vendor's patch.

## Is CVE-2026-89608 being exploited?

There is no known exploitation of CVE-2026-89608 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89608 and fix it if it is affected.

What it is: CVE-2026-89608 is a high-severity vulnerability in Linux, published on 11 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-2026-89608 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-2026-89608/ (Markdown: https://insights.sbomify.com/CVE-2026-89608/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89608
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89608
- OSV: https://osv.dev/vulnerability/CVE-2026-89608

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89608/
Summaries are generated and may contain mistakes; the official description above is the record.