5.5

CVE-2026-64207: net/sched: dualpi2: fix GSO backlog accounting

Analyzed
AliasesUBUNTU-CVE-2026-64207DEBIAN-CVE-2026-64207CGA-936c-6cx2-vvj5
Published 20-07-2026Last modified 17-08-2026

Vulnerability summary

CVE-2026-64207 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.16%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 13 · Related 13
MGASA-2026-0312OPENSUSE-SU-2026:11476-1USN-8726-1USN-8726-2USN-8726-3USN-8726-4

Timeline

  1. 20-07-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: dualpi2: fix GSO backlog accounting When DualPI2 splits a GSO skb into N segments, it propagates N additional packets to its parent before returning NET_XMIT_SUCCESS. The parent then accounts for the original skb once more, leaving its qlen one larger than the number of packets actually queued. With QFQ as the parent, after all real packets are dequeued, QFQ still has a non-zero qlen while its in-service aggregate has no active classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes the result to qfq_peek_skb(), causing a NULL pointer dereference. Follow the same pattern used by tbf_segment() and taprio: count only successfully queued segments, propagate the difference between the original skb and those segments, and return NET_XMIT_SUCCESS whenever at least one segment was queued.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.16%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

Increase +0.05 pp

From 0.11% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu119 products
  • linux< 7.0.0-31.31
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 7.0.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Chainguard2 products
  • linux-gcp-6.18< 6.18.44-r0
  • linux-gcp-6.18-bootc< 6.18.44-r0
Linux2 products
  • linux≥ 8f9516daedd67097a0c6e463fcb7a42b5ee9d477, < c4b70c1512b8f9f33f23c2c8196dfd1210207681 | ≥ 8f9516daedd67097a0c6e463fcb7a42b5ee9d477, < 806586e33891066487db1f002be3d455cda6b516 | ≥ 8f9516daedd67097a0c6e463fcb7a42b5ee9d477, < 05ed733b65ab977dd931e7f7ac0f62fdb81205c2 | 6.17
  • linux_kernel≥ 6.17, < 6.18.39 | ≥ 6.19, < 7.1.4
Debian1 product
  • linux< 7.1.4-1

4 vendors · 124 products

References

18 links
Show all 18 references