Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commits 967c05aee439e6e5d7d805e195b3a20ef5c433d6 and 5f3e2bf008c2221478101ee72f5cb4654b9fc363.

Related CVEs

CVE-2019-11479

Key Information

GHSA ID

GHSA-99cq-xr7g-h22w

Published

May 24, 2022 4:48 PM

Last Modified

August 16, 2023 3:30 PM

CVSS Score

7.5 /10

Primary Ecosystem

Unknown

Primary Package

Unknown

GitHub Reviewed

✗ No

Dataset

Last updated: June 14, 2025 6:24 AM

Data from GitHub Advisory Database. This information is provided for research and educational purposes.