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5.5
MEDIUM CVSS 3.1
CVE-2026-31623
net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete() A malicious USB device claiming to be a CDC Phonet modem can overflow the skb_shared_info->frags[] array by sending an unbounded sequence of full-page bulk transfers. Drop the skb and increment the length error when the frag limit is reached. This matches the same fix that commit f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") did for the t7xx driver.

Details
INFO

Published Date :

April 24, 2026, 3:16 p.m.

Last Modified :

June 1, 2026, 5:16 p.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-31623 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Fix skb frags overflow by dropping skb and incrementing length error on frag limit.
  • Apply the kernel patch to address skb frags overflow.
  • Update the Linux kernel to the resolved version.
  • Ensure the cdc-phonet driver is updated.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-31623.

URL Resource
https://git.kernel.org/stable/c/0c5c65a17db729fc63ab656bdaaf0e675a9dbeac
https://git.kernel.org/stable/c/600dc40554dc5ad1e6f3af51f700228033f43ea7 Patch
https://git.kernel.org/stable/c/6053620fdbcd89fa7e755644efdaab78e0daaae7
https://git.kernel.org/stable/c/6807ff49bf796b3823b1e29f97b69316a40a9a94
https://git.kernel.org/stable/c/9989938d13cc5ba8447eeed5a61acfcf61bc6801 Patch
https://git.kernel.org/stable/c/a23b1b1aaf41e174181d5853a70e65d4d01e648c Patch
https://git.kernel.org/stable/c/c183d5775129a0a7495bd61a6e57ec230dcf01e5 Patch
https://git.kernel.org/stable/c/d4e1946bea8d6441835eb3fd09b19237ba366a6f Patch
https://git.kernel.org/stable/c/ebf75c6301c4972a87542ebf2d994c6391eb5d46 Patch
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-31623 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-31623 weaknesses.

CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-42: MIME Conversion MIME Conversion CAPEC-44: Overflow Binary Resource File Overflow Binary Resource File CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-92: Forced Integer Overflow Forced Integer Overflow CAPEC-100: Overflow Buffers Overflow Buffers

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-31623 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-31623 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 01, 2026

    Action Type Old Value New Value
    Added Reference https://git.kernel.org/stable/c/0c5c65a17db729fc63ab656bdaaf0e675a9dbeac
    Added Reference https://git.kernel.org/stable/c/6053620fdbcd89fa7e755644efdaab78e0daaae7
    Added Reference https://git.kernel.org/stable/c/6807ff49bf796b3823b1e29f97b69316a40a9a94
  • Initial Analysis by [email protected]

    Apr. 28, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-120
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.24 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.14 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 7.0 up to (excluding) 7.0.1 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.83 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.31 up to (excluding) 6.6.136
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/600dc40554dc5ad1e6f3af51f700228033f43ea7 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/9989938d13cc5ba8447eeed5a61acfcf61bc6801 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/a23b1b1aaf41e174181d5853a70e65d4d01e648c Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/c183d5775129a0a7495bd61a6e57ec230dcf01e5 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/d4e1946bea8d6441835eb3fd09b19237ba366a6f Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/ebf75c6301c4972a87542ebf2d994c6391eb5d46 Types: Patch
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 27, 2026

    Action Type Old Value New Value
    Added Reference https://git.kernel.org/stable/c/d4e1946bea8d6441835eb3fd09b19237ba366a6f
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 27, 2026

    Action Type Old Value New Value
    Added Reference https://git.kernel.org/stable/c/600dc40554dc5ad1e6f3af51f700228033f43ea7
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 24, 2026

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete() A malicious USB device claiming to be a CDC Phonet modem can overflow the skb_shared_info->frags[] array by sending an unbounded sequence of full-page bulk transfers. Drop the skb and increment the length error when the frag limit is reached. This matches the same fix that commit f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") did for the t7xx driver.
    Added Reference https://git.kernel.org/stable/c/9989938d13cc5ba8447eeed5a61acfcf61bc6801
    Added Reference https://git.kernel.org/stable/c/a23b1b1aaf41e174181d5853a70e65d4d01e648c
    Added Reference https://git.kernel.org/stable/c/c183d5775129a0a7495bd61a6e57ec230dcf01e5
    Added Reference https://git.kernel.org/stable/c/ebf75c6301c4972a87542ebf2d994c6391eb5d46
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 5.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact