What is CVE-2025-21671?

CVE-2025-21671 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2025-01-31.

How severe is CVE-2025-21671?

High severity. CVSS v3 base score is 7.8 out of 10.

Is CVE-2025-21671 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Use After Free in Linux

CVE-2025-21671

In the Linux kernel, the following vulnerability has been resolved: zram: fix potential UAF of zram table If zram_meta_alloc failed early, it frees allocated zram->table without setting it NULL. Which will potentially cause zram_meta_free to access the table if user reset an failed and uninitialized device.

Vulnerability class: Use-After-Free

EPSS: 0.002 (11.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Linux — versions ac3b5366b9b7c9d97b606532ceab43d2329a22f3, 0b5b0b65561b34e6e360de317e4bcd031bfabf42, 6fb92e9a52e3feae309a213950f21dfcd1eb0b40
Linux Linux_kernel

Weakness classification (CWE)

CWE-416 — Use After Free

Public proof-of-concept exploits

References

416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2025-21671?: CVE-2025-21671 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2025-01-31.
How severe is CVE-2025-21671?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-21671 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.