# esp: do not unref managed frag pages in esp_ssg_unref()

CVE record · `CVE-2026-93105`

- **Identifiers:** `CVE-2026-93105`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 17 Sept 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 17 Sept 2026, 16:11 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: `cac2661c53f35cbe651bef9b07026a5a05ab8ce0 to before cb375965800d474c0281a2e92c43c724fce9f463` (git)
  - affected: `cac2661c53f35cbe651bef9b07026a5a05ab8ce0 to before 201bdf10ae92e7cbd524adf8c0323e2a963d5fd7` (git)
  - affected: `cac2661c53f35cbe651bef9b07026a5a05ab8ce0 to before 3ec55f0c8a6a543cf660584d1346e11f6311ee59` (git)
  - affected: `cac2661c53f35cbe651bef9b07026a5a05ab8ce0 to before 1ad6456898f6e6cf58be83bdb607acb1119a9cd1` (git)
  - affected: `cac2661c53f35cbe651bef9b07026a5a05ab8ce0 to before 26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf` (git)
  - affected: `cac2661c53f35cbe651bef9b07026a5a05ab8ce0 to before 21697720ff43b8dfa25b8e8d9ca7f56f4597fc80` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.11`
  - unaffected: `before 4.11` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.160 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.114 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.57 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.6 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.

> Linux kernel versions from 4.11 up to, but not including, the fixed releases (6.1.191, 6.6.160, 6.12.114, 6.18.57 and their stable series) are affected. The ESP IPsec output path can drop a page reference that the socket buffer never acquired when it carries managed frags, such as those from io_uring SEND_ZC with registered buffers. This can underflow the page reference count and free a page still in use. The source gives few details on how an attacker reaches this path. Upgrade to a fixed kernel version; no workaround is listed.

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

- 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 13 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 17 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-93105](https://www.cve.org/CVERecord?id=CVE-2026-93105)
- [NVD: CVE-2026-93105](https://nvd.nist.gov/vuln/detail/CVE-2026-93105)

### References from the CNA

- <https://git.kernel.org/stable/c/cb375965800d474c0281a2e92c43c724fce9f463>
- <https://git.kernel.org/stable/c/201bdf10ae92e7cbd524adf8c0323e2a963d5fd7>
- <https://git.kernel.org/stable/c/3ec55f0c8a6a543cf660584d1346e11f6311ee59>
- <https://git.kernel.org/stable/c/1ad6456898f6e6cf58be83bdb607acb1119a9cd1>
- <https://git.kernel.org/stable/c/26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf>
- <https://git.kernel.org/stable/c/21697720ff43b8dfa25b8e8d9ca7f56f4597fc80>

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-2026-93105>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-93105/>. Everything for agents: <https://agentprime.io/llms.txt>.