# net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen

CVE record · `CVE-2026-80630`

- **Identifiers:** `CVE-2026-80630`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 28 Aug 2026
- **Updated:** 16 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 28 Aug 2026, 06:48 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.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `cc71a757da78dd4aa1b4a9b19cb011833730ccf2 to before 3e515188393e62a718ccebee651ee74514104ff6` (git)
  - affected: `eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450 to before 20dd591d8f951e1e6aca5052be8785e6181055e2` (git)
  - affected: `829c49b6b2ff45b043739168fd1245e4e1a91a30 to before 94a5f1efdefb01f82cd228bf4e7ef1e8fc075c80` (git)
  - affected: `2f9761a94bae33d26e6a81b31b36e7d776d93dc1 to before acc08a0c7f37ebb1901144e03a7cba7d4afd9203` (git)
  - affected: `4d55144b12e742404bb3f8fee6038bafbf45619d to before 7c09843fd2b44d9bf0de798683861d1aecd62a08` (git)
  - affected: `342debc12183b51773b3345ba267e9263bdfaaef to before 0500af8630c3253f0dde879bd3a73a06bb2f2b3f` (git)
  - affected: `342debc12183b51773b3345ba267e9263bdfaaef to before af54df2f44d9605614bc7ed96640302a240a9a62` (git)
  - affected: `342debc12183b51773b3345ba267e9263bdfaaef to before 097f6fc7b1ae362dd7a9444b2572162fda73b284` (git)
  - affected: `7a742a9506849d1c1aa71e36c89855ceddc7d58e` (git)
  - affected: `e73c838c80dccb9e4f19becc11d9f3cb4a27d483` (git)
  - affected: `a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31` (git)
  - affected: `5.10.241 to before 5.10.261` (semver)
  - and 7 more
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.15`
  - unaffected: `before 6.15` (semver)
  - unaffected: `5.10.261 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.212 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.178 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.145 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.97 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.40 to 6.18.*, inclusive` (semver)
  - unaffected: `7.1.5 to 7.1.*, inclusive` (semver)
  - unaffected: `7.2 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0076, the 55th percentile, on 15 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 28 Aug 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-80630](https://www.cve.org/CVERecord?id=CVE-2026-80630)
- [NVD: CVE-2026-80630](https://nvd.nist.gov/vuln/detail/CVE-2026-80630)

### References from the CNA

- <https://git.kernel.org/stable/c/3e515188393e62a718ccebee651ee74514104ff6>
- <https://git.kernel.org/stable/c/20dd591d8f951e1e6aca5052be8785e6181055e2>
- <https://git.kernel.org/stable/c/94a5f1efdefb01f82cd228bf4e7ef1e8fc075c80>
- <https://git.kernel.org/stable/c/acc08a0c7f37ebb1901144e03a7cba7d4afd9203>
- <https://git.kernel.org/stable/c/7c09843fd2b44d9bf0de798683861d1aecd62a08>
- <https://git.kernel.org/stable/c/0500af8630c3253f0dde879bd3a73a06bb2f2b3f>
- <https://git.kernel.org/stable/c/af54df2f44d9605614bc7ed96640302a240a9a62>
- <https://git.kernel.org/stable/c/097f6fc7b1ae362dd7a9444b2572162fda73b284>

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-2026-80630>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-80630/>. Everything for agents: <https://agentprime.io/llms.txt>.