CVE-2026-31616
MediumIn the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_phonet: fix skb frags[] overflow in pn_rx_complete() A broken/bored/mean USB host can overflow the skb_shared_info->frags[] array on a Linux gadget exposing a Phonet function by sending an unbounded sequence of full-page OUT transfers. pn_rx_complete() finalizes the skb only when req->actual < req->length, where req->length is set to PAGE_SIZE by the gadget. If the host always sends exactly PAGE_SIZE bytes per transfer, fp->rx.skb will never be reset and each completion will add another fragment via skb_add_rx_frag(). Once nr_frags exceeds MAX_SKB_FRAGS (default 17), subsequent frag stores overwrite memory adjacent to the shinfo on the heap. Drop the skb and account a length error when the frag limit is reached, matching the fix applied in t7xx by commit f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path").
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-401CVE-2026-31616 is a Memory Leak vulnerability
What is Memory Leak?
The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE
Affected versions
Linux kernel versions
2.6.32
and later are affected. Fixed in
5.10.258,
5.15.209,
6.1.175,
6.6.136,
6.12.83,
6.18.24,
6.19.14,
7.0.1,
7.1-rc1
and their respective stable series.
References
The following references provide additional information about CVE-2026-31616 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
-
PatchKernel patch commithttps://git.kernel.org/stable/c/3d7f7e0c842242878c24b2facff8d6eda23ee1e9
-
PatchKernel patch commithttps://git.kernel.org/stable/c/4e476c25bfcab0535ba7c76a903ae77ca8747711
-
PatchKernel patch commithttps://git.kernel.org/stable/c/66f7471c4042e4eb300e30b5b9d87d1406862673
Frequently asked questions
-
What is CVE-2026-31616?
CVE-2026-31616 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 2.6.32 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-31616 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
What is the CVSS score for CVE-2026-31616?
CVE-2026-31616 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-31616?
Yes — CVE-2026-31616 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 2.6.32 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2026-31616 actively exploited?
No — CVE-2026-31616 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
-
What is Memory Leak (CWE-401)?
The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →