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CVE-2026-53175

Use After Free: Is CVE-2026-53175 real, exploitable, or a false positive? Here's the community verdict.

signals

public sources

Exploited in wild
Not listed
CISA KEV
Public exploit
None known
Metasploit/EDB/PoC
Base severity
9.8 Critical
CVSS
Exploitation prob.
0.3%
FIRST EPSS
Weakness
CWE-416 · Use After Free
CWE

High CVSS base score, but low real-world exploitation probability (EPSS). Likely less urgent than the score implies.

baseline read

auto · not a community verdict

Real, but low real-world risk

A genuine vulnerability on paper, but EPSS shows little real-world exploitation — the base score may overstate urgency. This is not the same as a false positive.

Based on CVSS · FIRST EPSS

Confirm or dispute →

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

In the Linux kernel, the following vulnerability has been resolved: inet: frags: fix use-after-free caused by the fqdir_pre_exit() flush On netns teardown, fqdir_pre_exit() walks the fqdir rhashtable and flushes every fragment queue that is not yet complete using inet_frag_queue_flush(). That helper frees all the skbs queued on the fragment queue but does not set INET_FRAG_COMPLETE, and leaves q->fragments_tail and q->last_run_head pointing at the freed skbs. The queue itself stays in the rhashtable. fqdir_pre_exit() first lowers high_thresh to 0 to stop new queue lookups, but it cannot stop a fragment that already obtained the queue through inet_frag_find() earlier and stalled just before taking the queue lock. Once that fragment resumes after the flush and takes the queue lock, it passes the INET_FRAG_COMPLETE check and then dereferences the freed fragments_tail. inet_frag_queue_insert() reads FRAG_CB() and ->len of that pointer and, on the append path, writes ->next_frag, causing a slab use-after-free. IPv6, nf_conntrack_reasm6 and 6lowpan reassembly share the same flush path and are affected as well. Reset rb_fragments, fragments_tail and last_run_head in inet_frag_queue_flush() so a flushed queue no longer points at the freed skbs. A fragment that resumes after the flush and takes the queue lock then finds an empty queue and starts a new run instead of dereferencing the freed fragments_tail. ip_frag_reinit() already performed this reset after its own flush, so drop the now duplicate code there.

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    Same weakness: CWE-416 · Use After Free.