CVE-2026-64452 (CVSS 7.1)

Description

In the Linux kernel, the following vulnerability has been resolved: 6lowpan: fix NHC entry use-after-free on error path lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding lowpan_nhc_lock. If the descriptor has no uncompress callback, the error path drops the lock before printing nhc->name. lowpan_nhc_del() removes descriptors under the same lock and then relies on synchronize_net() before the owning module can be unloaded. That only waits for net RX RCU readers. lowpan_header_decompress() is also exported and can be reached from callers that are not necessarily covered by the net core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive path. This leaves a race where one task drops lowpan_nhc_lock in the error path, another task unregisters and frees the matching descriptor after synchronize_net() returns, and the first task then dereferences nhc->name for the warning. With the post-unlock window widened, KASAN reports: BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220 Read of size 8 lowpan_nhc_do_uncompression lowpan_header_decompress Fix this by printing the warning before dropping lowpan_nhc_lock, so the descriptor name is read while unregister is still excluded. The malformed packet is still rejected with -ENOTSUPP.

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CVSS v3.1 Score

7.1

HIGH

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

EPSS — Exploit Prediction

0.0022

Probability of exploitation

0.12%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/0beccbcf50de125be5520d0ffc59af4bb8655482 https://git.kernel.org/stable/c/1720db928e5a58ca7d75ac1d514c3b73fd7061a7 https://git.kernel.org/stable/c/593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168 https://git.kernel.org/stable/c/80b5c8779acee0550845394fb3e5176a398aa24c https://git.kernel.org/stable/c/9c2f5c0829a8c8b904dae36be6d8056b719ac605 https://git.kernel.org/stable/c/a8e3a94711134e898c6021a6b77374efa91b3639 https://git.kernel.org/stable/c/b713aa0cc344f10f7a9928a230b5f5e780d04078 https://git.kernel.org/stable/c/cc27aea4d454abfb385ee2c9499c78b96db9b728

Frequently Asked Questions

What is CVE-2026-64452? +

In the Linux kernel, the following vulnerability has been resolved: 6lowpan: fix NHC entry use-after-free on error path lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding lowpan_nhc_lock. If the descriptor has no uncompress callback, the error path drops the lock before printing nhc->name. lowpan_nhc_del() removes descriptors under the same lock and then relies on synchronize_net() before the owning module can be unloaded. That only waits for net RX RCU readers. lowpan_header_decompress() is also exported and can be reached from callers that are not necessarily covered by the net core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive path. This leaves a race where one task drops lowpan_nhc_lock in the error path, another task unregisters and frees the matching descriptor after synchronize_net() returns, and the first task then dereferences nhc->name for the warning. With the post-unlock window widened, KASAN reports: BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220 Read of size 8 lowpan_nhc_do_uncompression lowpan_header_decompress Fix this by printing the warning before dropping lowpan_nhc_lock, so the descriptor name is read while unregister is still excluded. The malformed packet is still rejected with -ENOTSUPP. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2026-64452? +

CVE-2026-64452 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0022, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-64452? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-64452