Vulnary
← back to the feed
Critical· 9.8official fix available

CVE-2021-46999

This vulnerability is a critical use‑after‑free bug in the Linux kernel’s SCTP implementation. It can cause a kernel panic, crashing the system. The issue has been fixed in a kernel patch.

publishedFeb 28, 2024
last modifiedAug 4, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
51th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Sep 4, 2026

An official fix is available, so this entry is kept for 30 days and then removed automatically.

01

Who is affected

Linux kernel (all versions before the patch) on systems that use the SCTP protocol. Typical users include Linux administrators and developers who run network services that rely on SCTP.

02

Real-world impact

An attacker could trigger a kernel panic, causing a denial of service by crashing the system.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability is exploitable remotely with no authentication or user interaction. It can lead to complete loss of confidentiality, integrity, and availability, making it a critical threat.

04

What to do about it

official fix available
recommended steps
  1. 01Upgrade your Linux kernel to a version that includes the fix for CVE-2021-46999.
  2. 02Reboot the system to load the updated kernel.

NVD-referenced vendor advisory

05

Timeline

  1. Feb 28, 2024 · Feb 28, 2024
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Aug 4, 2026 · 2d ago
    Advisory updated
    The NVD record was last revised.
  3. Aug 5, 2026 · 14h ago
    Official fix available
    A vendor patch or mitigation now exists — see the remediation steps above.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Privileges requiredNone
User interactionNone needed
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
07

References & advisories

(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →