CVE-2023-53559 | ip_vti: fix potential slab-use-after-free in decode_session6

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.

Published: 2025-10-04 Last update: 2026-03-21 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-53559 is rated Low Risk (33.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-53559

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-10-05 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-53559

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2023-53559

OS Trackers for CVE-2023-53559

vendor priority summary link
debian not yet assigned CVE-2023-53559 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-53559
redhat medium — https://access.redhat.com/security/cve/CVE-2023-53559
suse medium — https://www.suse.com/security/cve/CVE-2023-53559/
ubuntu medium CVE-2023-53559 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 161, released 138, not-affected 78, needed 19, needs-triage 1. https://ubuntu.com/security/CVE-2023-53559

Affected software / configurations for CVE-2023-53559

Vendor Product Version Raw CPE
linux linux_kernel >= 3.19.1, < 4.14.324 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.15, < 4.19.293 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.20, < 5.4.255 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.192 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.128 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.47 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.4.12 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 3.19 cpe:2.3:o:linux:linux_kernel:3.19:-:*:*:*:*:*:*
linux linux_kernel 3.19 cpe:2.3:o:linux:linux_kernel:3.19:rc7:*:*:*:*:*:*
linux linux_kernel 6.5 cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:*
linux linux_kernel 6.5 cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:*
linux linux_kernel 6.5 cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:*
linux linux_kernel 6.5 cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:*
linux linux_kernel 6.5 cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:*
linux linux_kernel 6.5 cpe:2.3:o:linux:linux_kernel:6.5:rc6:*:*:*:*:*:*

References for CVE-2023-53559

cvelogic Threat Intelligence