CVE-20XX-?
agent?

CVE-2021-22555

8.3 HIGH 79% exploit odds exploited in the wild Fix listed Memory safety Device

What it is

A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space

At a glance

Exploitability
Can be exploited from the same network segment without logging in. High risk of data exposure, data tampering, service disruption.
In the wild
CISA lists this as exploited in real attacks. Treat as urgent.
Fix
A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

  1. ReservedThe CVE id was reserved by its CNA
  2. PublishedDisclosed publicly on CVE.org and NVD
  3. Fix referencedNVD first recorded a patch, advisory or mitigation link
  4. 2025-10-06 Exploited in the wildAdded to CISA's Known Exploited Vulnerabilities list
  5. 2025-10-27 Remediation deadlineCISA's due date for federal agencies to fix it
  6. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Added to CISA KEV
2025-10-06
Exploit probability
78.7% · EPSS, next 30 days
Weakness
CWE-787 · Out-of-bounds write
Record status
Analyzed

Affected

Attack profile CVSS 3.1 · 8.3

Attack vector
Adjacent network
Complexity
High
Privileges needed
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-22555.md and follow it. Check whether this project is affected by CVE-2021-22555. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

· More options · Status badge

Meme: I wake up, CVE-2021-22555
Download Square Reddit

Fix and advisories

References

NVD record · CVE.org record