# arm64: tlb: Flush walk cache when unsharing PMD tables

CVE record · `CVE-2026-63875`

- **Identifiers:** `CVE-2026-63875`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **Critical:** No
- **CNA:** Linux
- **Weakness (CWE):** [CWE-459](https://cwe.mitre.org/data/definitions/459.html)
- **Tags:** [CWE-459](https://agentprime.io/advisories/tag/cwe-459.md)
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 19 Jul 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 19 Jul 2026, 14:54 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: `6495204f8219a57859669d618b25d06176d5a872 to before dced308d7d6a0de1c09d2058f38f1aaaf5cbb914` (git)
  - affected: `ce4cf24761467756462c0e1dbe4a5e9c9eb520fc to before 47490bbb05c8c0e09cc3cfd237d8934ffc340583` (git)
  - affected: `daa6707b71a2da23a82979fa21f788aeb706f1a2 to before 0199c9d57861f17b556b6cba1f765c7cce79745b` (git)
  - affected: `ff37dd18ce7739a26aab0cc2d31006a45e6bde63 to before d766a49d9b55705c4737cd8bb5d3faa2d31330fd` (git)
  - affected: `da06bb0ca45b1ca6f1ab55023e34e61a520337f3 to before 8ca7284da0e67b3e71d90ec17f08286774245ad9` (git)
  - affected: `9b671f6f432be07c0ddd66e437d6d0e0db684f83 to before fe93e907b1af03cc229a80aa64a570a103d2b279` (git)
  - affected: `8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1 to before 48125cd9c55cbe297b59fd1f9bda48b0960bd181` (git)
  - affected: `8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1 to before c2ff4764e03e7a8d758352f4aceb8fe1be6ac971` (git)
  - affected: `5.10.253 to before 5.10.259` (semver)
  - affected: `5.15.203 to before 5.15.210` (semver)
  - affected: `6.1.167 to before 6.1.176` (semver)
  - affected: `6.6.127 to before 6.6.143` (semver)
  - and 2 more
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.19`
  - unaffected: `before 6.19` (semver)
  - unaffected: `5.10.259 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.210 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.176 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.143 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.93 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.35 to 6.18.*, inclusive` (semver)
  - unaffected: `7.0.12 to 7.0.*, inclusive` (semver)
  - unaffected: `7.1 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## 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

- 7.8 High, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`, from CNA (Linux)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0018, the 7th percentile, on 7 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 19 Jul 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-63875](https://www.cve.org/CVERecord?id=CVE-2026-63875)
- [NVD: CVE-2026-63875](https://nvd.nist.gov/vuln/detail/CVE-2026-63875)

### References from the CNA

- <https://git.kernel.org/stable/c/dced308d7d6a0de1c09d2058f38f1aaaf5cbb914>
- <https://git.kernel.org/stable/c/47490bbb05c8c0e09cc3cfd237d8934ffc340583>
- <https://git.kernel.org/stable/c/0199c9d57861f17b556b6cba1f765c7cce79745b>
- <https://git.kernel.org/stable/c/d766a49d9b55705c4737cd8bb5d3faa2d31330fd>
- <https://git.kernel.org/stable/c/8ca7284da0e67b3e71d90ec17f08286774245ad9>
- <https://git.kernel.org/stable/c/fe93e907b1af03cc229a80aa64a570a103d2b279>
- <https://git.kernel.org/stable/c/48125cd9c55cbe297b59fd1f9bda48b0960bd181>
- <https://git.kernel.org/stable/c/c2ff4764e03e7a8d758352f4aceb8fe1be6ac971>

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-2026-63875>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-63875/>. Everything for agents: <https://agentprime.io/llms.txt>.