CVE-2026-53270

Description

In the Linux kernel, the following vulnerability has been resolved: ipvs: clear the svc scheduler ptr early on edit ip_vs_edit_service() while unbinding the old scheduler clears the svc->scheduler ptr after the scheduler module initiates RCU callbacks. This can cause packets to use the old scheduler at the time when svc->sched_data is already freed after RCU grace period. Fix it by clearing the ptr early in ip_vs_unbind_scheduler(), before the done_service method schedules any RCU callbacks. Also, if the new scheduler fails to initialize when replacing the old scheduler, try to restore the old scheduler while still returning the error code.

CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/14e4689c113b4c06af1069364ade24fdd7055f33 https://git.kernel.org/stable/c/193989cc6d80dd8e0460fb3992e69fa03bf0ff9b https://git.kernel.org/stable/c/19a9493faa4bf3c7bd0a386f30b60b1bb4a3da03 https://git.kernel.org/stable/c/25918720ba97f974a4f8d433b5a0132c5b43f6f3 https://git.kernel.org/stable/c/7d4f5004511757e3984901ffb412fcf858d80ed5 https://git.kernel.org/stable/c/c6376b9b1b4d2bad638256b1b3588e073344ae69 https://git.kernel.org/stable/c/d10730a1f2caf08088e0db1b19b242f3e6fa5f06 https://git.kernel.org/stable/c/e4feec3174036ba772006be74beee0efa09a9eb8

Frequently Asked Questions

What is CVE-2026-53270? +

In the Linux kernel, the following vulnerability has been resolved: ipvs: clear the svc scheduler ptr early on edit ip_vs_edit_service() while unbinding the old scheduler clears the svc->scheduler ptr after the scheduler module initiates RCU callbacks. This can cause packets to use the old scheduler at the time when svc->sched_data is already freed after RCU grace period. Fix it by clearing the ptr early in ip_vs_unbind_scheduler(), before the done_service method schedules any RCU callbacks. Also, if the new scheduler fails to initialize when replacing the old scheduler, try to restore the old scheduler while still returning the error code. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-53270? +

CVE-2026-53270 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-53270? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.