Linux Kernel Privilege Escalation Vulnerability
A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 2 / 5
- KEV catalog (CISA)11 Apr 2022
- Exploited in EUVD (ENISA)11 Apr 2022
- Used by ransomwareno
- EPSS above 10 %6.6%
- No account, over the networkno
What to do
Fix
Update to a fixed version: 5.15.15-1
CISA guidance: Apply updates per vendor instructions.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755
Affected products
- unspecified <5.15.11
- unspecified <5.4.168
- unspecified <5.16-rc6
- unspecified <5.10.88
Open source packages OSV
- linuxDebian:12 · CVE-2021-22600fixed in 5.15.15-1
- linuxDebian:13 · CVE-2021-22600fixed in 5.15.15-1
Timeline
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Published
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Exploitation reported (ENISA)
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Added to the KEV catalog
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CISA remediation due date
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-46300Linux Kernel Missing Initialization of a Variable Vulnerability5.4 · Rising fast
- CVE-2026-53266Linux Kernel Out-of-Bounds Write Vulnerability4.7 · Actively exploited
- CVE-2025-39964Linux Kernel Race Condition Vulnerability4.4 · Actively exploited
- CVE-2025-39682Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability5.8 · Actively exploited
- CVE-2026-53362Linux Kernel Unspecified Vulnerability4.3 · Actively exploited
- CVE-2022-0995Linux Kernel Out-of-Bounds Write Vulnerability4.6 · Actively exploited