# tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack()

CVE record · `CVE-2026-98374`

- **Identifiers:** `CVE-2026-98374`
- **State:** Confirmed
- **Severity:** CVSS 8.8 High
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 7 Oct 2026
- **Updated:** 24 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 7 Oct 2026, 13:01 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: `c31b70c9968fe9c4194d1b5d06d07596a3b680de to before fad6d429651e748365e93ca54645accc212f0018` (git)
  - affected: `c31b70c9968fe9c4194d1b5d06d07596a3b680de to before c5b4da1f403a658c1c19766be2b426003ada419f` (git)
  - affected: `c31b70c9968fe9c4194d1b5d06d07596a3b680de to before 71d45049b0d631dfdbf3c65305f7fca676de023b` (git)
  - affected: `c31b70c9968fe9c4194d1b5d06d07596a3b680de to before e3ea71cb1408a013ed4e8a757b815f1a919324bd` (git)
  - affected: `c31b70c9968fe9c4194d1b5d06d07596a3b680de to before 631aa4cb45099f09e9385dd786bd291c6270bfc4` (git)
  - affected: `c31b70c9968fe9c4194d1b5d06d07596a3b680de to before 0f87720c7e4bcab07c24888b3cf12bfe857bb90e` (git)
  - affected: `c31b70c9968fe9c4194d1b5d06d07596a3b680de to before fe99bbeee5c5dbd3abc30721a8079ced59649d97` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `5.11`
  - unaffected: `before 5.11` (semver)
  - unaffected: `5.15.222 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.189 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.158 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.112 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.55 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.9 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0029, the 22nd percentile, on 8 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 7 Oct 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-98374](https://www.cve.org/CVERecord?id=CVE-2026-98374)
- [NVD: CVE-2026-98374](https://nvd.nist.gov/vuln/detail/CVE-2026-98374)

### References from the CNA

- <https://git.kernel.org/stable/c/fad6d429651e748365e93ca54645accc212f0018>
- <https://git.kernel.org/stable/c/c5b4da1f403a658c1c19766be2b426003ada419f>
- <https://git.kernel.org/stable/c/71d45049b0d631dfdbf3c65305f7fca676de023b>
- <https://git.kernel.org/stable/c/e3ea71cb1408a013ed4e8a757b815f1a919324bd>
- <https://git.kernel.org/stable/c/631aa4cb45099f09e9385dd786bd291c6270bfc4>
- <https://git.kernel.org/stable/c/0f87720c7e4bcab07c24888b3cf12bfe857bb90e>
- <https://git.kernel.org/stable/c/fe99bbeee5c5dbd3abc30721a8079ced59649d97>

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-2026-98374>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-98374/>. Everything for agents: <https://agentprime.io/llms.txt>.