CVE entry · CVE-2021-22555
CVE-2021-22555: Linux Kernel Heap Out-of-Bounds Write Vulnerability
Linux Kernel contains a heap out-of-bounds write vulnerability that could allow an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space.
- Actively exploited: added to CISA’s KEV catalog on October 6, 2025.
- Use by ransomware: not established so far.
- Remediation deadline for US federal agencies: October 27, 2025.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes Linux Kernel, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.
References
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (security.netapp.com)
- Vendor advisory or reference cited by CISA (github.com)
- NVD entry (NIST)
- CISA KEV catalog
Other Linux vulnerabilities
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Linux Kernel Out-of-Bounds Write Vulnerability
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Linux Kernel Race Condition Vulnerability
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Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability
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Linux Kernel Unspecified Vulnerability
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Linux Kernel Out-of-Bounds Write Vulnerability
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Linux Kernel Improper Authentication Vulnerability