How severe is CVE-2023-53559?

CVE-2023-53559 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-2023-53559 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-53559?

CVE-2023-53559 primarily affects Linux Linux Kernel. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-53559?

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.

Does CVE-2023-53559 have an EU (EUVD) identifier?

Yes. CVE-2023-53559 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-32314.

When was CVE-2023-53559 published?

CVE-2023-53559 was published on 2025-10-04 and last updated on 2026-06-17.

CVE-2023-53559

CVE-2023-53559 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-416.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-32314
Weakness: CWE-416
Affected product: Linux Linux Kernel
Published: 2025-10-04
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: ip_vti: fix potential slab-use-after-free in decode_session6 When ip_vti device is set to the qdisc of the sfb type, the cb field of the sent skb may be modified during enqueuing. Then, slab-use-after-free may occur when ip_vti device sends IPv6 packets. As commit f855691975bb ("xfrm6: Fix the nexthdr offset in _decode_session6.") showed, xfrm_decode_session was originally intended only for the receive path. IP6CB(skb)->nhoff is not set during transmission. Therefore, set the cb field in the skb to 0 before sending packets.

Frequently asked questions

What is CVE-2023-53559?: In the Linux kernel, the following vulnerability has been resolved: ip_vti: fix potential slab-use-after-free in decode_session6 When ip_vti device is set to the qdisc of the sfb type, the cb field of the sent skb may be modified during enqueuing. Then, slab-use-after-free may occur when ip_vti device sends IPv6 packets. As commit f855691975bb ("xfrm6: Fix the nexthdr offset in _decode_session6.") showed, xfrm_decode_session was originally intended only for the receive path. IP6CB(skb)->nhoff is not set during transmission. Therefore, set the cb field in the skb to 0 before sending packets.
How severe is CVE-2023-53559?: CVE-2023-53559 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-2023-53559 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-53559?: CVE-2023-53559 primarily affects Linux Linux Kernel. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-53559?: 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.
Does CVE-2023-53559 have an EU (EUVD) identifier?: Yes. CVE-2023-53559 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-32314.
When was CVE-2023-53559 published?: CVE-2023-53559 was published on 2025-10-04 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.19:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.19:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc6:*:*:*:*:*:*

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