5.5

CVE-2026-31623: linux Classic Buffer Overflow

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2026-31623DEBIAN-CVE-2026-31623CGA-2v87-5qc9-jg3m
Published 24-04-2026Last modified 14-06-2026
Open JSON

Vulnerability summary

CVE-2026-31623 is a medium (CVSS 5.5) Classic Buffer Overflow vulnerability in linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.5% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.17%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 45 · Related 46
OPENSUSE-SU-2026:10703-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:23066-1SUSE-SU-2026:23068-1SUSE-SU-2026:23193-1SUSE-SU-2026:23194-1

Timeline

  1. 24-04-2026
    PublishedVulnerability first disclosed.
  2. 14-06-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

+0.04 pp

From 0.13% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.17%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu158 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-27.27
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64 | < 7.0.0-1008.8
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Chainguard10 products
  • linux-aws-6.12< 6.12.85-r0
  • linux-aws-6.18< 6.18.31-r0
  • linux-azure-6.18< 6.18.31-r0
  • linux-gcp-6.12< 6.12.85-r0
  • linux-gcp-6.18< 6.18.31-r0
Linux2 products
  • linux≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < 6807ff49bf796b3823b1e29f97b69316a40a9a94 | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < 0c5c65a17db729fc63ab656bdaaf0e675a9dbeac | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < 6053620fdbcd89fa7e755644efdaab78e0daaae7 | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < d4e1946bea8d6441835eb3fd09b19237ba366a6f | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < a23b1b1aaf41e174181d5853a70e65d4d01e648c | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < c183d5775129a0a7495bd61a6e57ec230dcf01e5 | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < ebf75c6301c4972a87542ebf2d994c6391eb5d46 | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < 9989938d13cc5ba8447eeed5a61acfcf61bc6801 | ≥ 87cf65601e1709e57f7e28f0f7b3eb0a992c1782, < 600dc40554dc5ad1e6f3af51f700228033f43ea7 | 2.6.31
  • linux_kernel≥ 2.6.31, < 6.6.136 | ≥ 6.7, < 6.12.83 | ≥ 6.13, < 6.18.24 | ≥ 6.19, < 6.19.14 | ≥ 7.0, < 7.0.1
Debian1 product
  • linux< 6.1.176-1 | < 6.12.85-1 | < 6.19.14-1

4 vendors · 171 products

References

46 links
Show all 46 references