How severe is CVE-2023-3611?

CVE-2023-3611 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-3611 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-3611?

CVE-2023-3611 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-3611?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-3611 published?

CVE-2023-3611 was published on 2023-07-21 and last updated on 2026-06-17.

CVE-2023-3611

CVE-2023-3611 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (19th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Linux Linux Kernel
Published: 2023-07-21
Last modified: 2026-06-17

Description

An out-of-bounds write vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. The qfq_change_agg() function in net/sched/sch_qfq.c allows an out-of-bounds write because lmax is updated according to packet sizes without bounds checks. We recommend upgrading past commit 3e337087c3b5805fe0b8a46ba622a962880b5d64.

Frequently asked questions

What is CVE-2023-3611?: An out-of-bounds write vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. The qfq_change_agg() function in net/sched/sch_qfq.c allows an out-of-bounds write because lmax is updated according to packet sizes without bounds checks. We recommend upgrading past commit 3e337087c3b5805fe0b8a46ba622a962880b5d64.
How severe is CVE-2023-3611?: CVE-2023-3611 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-3611 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-3611?: CVE-2023-3611 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-3611?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-3611 published?: CVE-2023-3611 was published on 2023-07-21 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*

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