Use After Free in Linux
CVE-2026-53248
In the Linux kernel, the following vulnerability has been resolved: net: airoha: Fix use-after-free in metadata dst teardown airoha_metadata_dst_free() runs metadata_dst_free() which frees the metadata_dst with kfree() immediately, bypassing the RCU grace period. In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from the skb to the metadata_dst. This function requires RCU read-side protection and the dst must remain valid until all RCU readers complete. Since metadata_dst_free() calls kfree() directly, an use-after-free can occur if any skb still holds a noref pointer to the dst when the driver tears it down. Replace metadata_dst_free() with dst_release() which properly goes through the refcount path: when the refcount drops to zero, it schedules the actual free via call_rcu_hurry(), ensuring all RCU readers have completed before the memory is freed.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (26.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.002
Affected products
- Linux — versions af3cf757d5c99011b9b94ea8d78aeaccc0153fdc, 6.15, 0
- Linux Kernel — versions 7.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-53248?
- CVE-2026-53248 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 8.8/10. Published 2026-06-25.
- How severe is CVE-2026-53248?
- High severity. CVSS v3 base score is 8.8 out of 10.