# f2fs: fix to migrate all curseg types during free_segment_range

CVE record · `CVE-2026-89834`

- **Identifiers:** `CVE-2026-89834`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 16 Sept 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 16 Sept 2026, 10:31 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to before 7ffac0deea2d84cf79051f16fed8e215c4bcf0e6` (git)
  - affected: `d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to before d358d2fc6be11eefde5eb1286f1c43a6d0330db6` (git)
  - affected: `d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to before 3b85edf3391f3e1f624f409a7d2d239885f567b7` (git)
  - affected: `d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to before b8ae1228c153622afa71a179c9d4dc268117e0f0` (git)
  - affected: `d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to before b9776094aa7118e8e5dfdcd791ffc8330c5ca408` (git)
  - affected: `d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to before 8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `5.10`
  - unaffected: `before 5.10` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.160 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.110 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.51 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.5 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The Linux kernel f2fs filesystem, from 5.10 before the fixes, does not migrate all active in-memory segments when shrinking a filesystem, so later writes can perform out-of-bounds I/O on the truncated storage. The source gives few details on what an attacker needs to trigger this. Upgrade to 6.1.191, 6.6.160, 6.12.110, 6.18.51, or a later release in those series.

Written 12 Nov 2026.

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

No source has published a CVSS score for this record yet.

- **CISA KEV:** Not listed.
- **EPSS:** 0.0022, the 11th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 16 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89834](https://www.cve.org/CVERecord?id=CVE-2026-89834)
- [NVD: CVE-2026-89834](https://nvd.nist.gov/vuln/detail/CVE-2026-89834)

### References from the CNA

- <https://git.kernel.org/stable/c/7ffac0deea2d84cf79051f16fed8e215c4bcf0e6>
- <https://git.kernel.org/stable/c/d358d2fc6be11eefde5eb1286f1c43a6d0330db6>
- <https://git.kernel.org/stable/c/3b85edf3391f3e1f624f409a7d2d239885f567b7>
- <https://git.kernel.org/stable/c/b8ae1228c153622afa71a179c9d4dc268117e0f0>
- <https://git.kernel.org/stable/c/b9776094aa7118e8e5dfdcd791ffc8330c5ca408>
- <https://git.kernel.org/stable/c/8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89834>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89834/>. Everything for agents: <https://agentprime.io/llms.txt>.