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
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Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2025-10-06), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.3 retained for reference. Confidence: HIGH.
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
July 7, 2021
October 27, 2025
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
RHSA-2021:3044 — Important
RHSA-2021:3057 — Important
RHSA-2021:3088 — Important
RHSA-2021:3173 — Important
RHSA-2021:3181 — Important
RHSA-2021:3235 — Important
RHSA-2021:3321 — Important
RHSA-2021:3327 — Important
RHSA-2021:3328 — Important
RHSA-2021:3363 — Important
RHSA-2021:3375 — Important
RHSA-2021:3380 — Important
RHSA-2021:3381 — Important
RHSA-2021:3399 — Important
RHSA-2021:3477 — Important
RHSA-2021:3522 — Important
RHSA-2021:3523 — Important
RHSA-2021:3725 — Important
RHSA-2021:3812 — Important
RHSA-2021:3814 — Important
RHSA-2025:17733 — Important
Kernel Live Patch Security Notice
Kernel Live Patch Security Notice
Kernel Live Patch Security Notice
Linux kernel vulnerability
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Working exploit code is in the public domain (1 Metasploit module) (4 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
This repo hosts TUKRU's Linux Privilege Escalation exploit (CVE-2021-22555). It demonstrates gaining root privileges via a vulnerability. Tested on Ubuntu 5.8.0-48-generic and COS 5.4.89+. Use responsibly and ethically.
Open source ↗CVE-2021-22555 exploit rewritten with pipe primitive
Open source ↗CVE-2021-22555 Exploit
Open source ↗Linux Kernel 2.6.19 < 5.9 - 'Netfilter Local Privilege Escalation
Open source ↗Netfilter x_tables Heap OOB Write Privilege Escalation
Open source ↗See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-22555
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.
redhat
CWE-787