CVE-2021-44879: linux linux_kernel NULL Pointer Dereference
Vulnerability summary
CVE-2021-44879 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux linux_kernel. EPSS estimates a 1.48% chance of exploitation in the next 30 days, higher than 73.9% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 26 · Related 23Timeline
- 13-02-2022PublishedVulnerability first disclosed.
- 14-10-2026Last modifiedVulnerability information updated.
Description
In gc_data_segment in fs/f2fs/gc.c in the Linux kernel before 5.16.3, special files are not considered, leading to a move_data_page NULL pointer dereference.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS trend
Probability
1.48%
Chance of exploitation in the next 30 days
Percentile
74%
Versus all other CVEs
30-day change
Increase +0.25 pp
From 1.23% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundExploit Reference (bugzilla.kernel.org)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu69 products
- linuxAll versions (No fix recorded) | < 5.4.0-173.191
- linux-awsAll versions (No fix recorded) | < 5.4.0-1120.130
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
- linux-aws-5.13< 5.13.0-1022.24~20.04.1
Debian1 product
- linux< 5.16.7-1
Linux1 product
- linux_kernel< 5.16.3
3 vendors · 71 products
