How severe is CVE-2026-43173?

CVE-2026-43173 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-43173 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43173?

CVE-2026-43173 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-43173?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-43173 have an EU (EUVD) identifier?

Yes. CVE-2026-43173 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27734.

When was CVE-2026-43173 published?

CVE-2026-43173 was published on 2026-05-06 and last updated on 2026-06-17.

CVE-2026-43173

CVE-2026-43173 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. 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-476.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-27734
Weakness: CWE-476
Affected product: Linux Linux Kernel
Published: 2026-05-06
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: net: ethernet: xscale: Check for PTP support properly In ixp4xx_get_ts_info() ixp46x_ptp_find() is called unconditionally despite this feature only existing on ixp46x, leading to the following splat from tcpdump: root@OpenWrt:~# tcpdump -vv -X -i eth0 (...) Unable to handle kernel NULL pointer dereference at virtual address 00000238 when read (...) Call trace: ptp_clock_index from ixp46x_ptp_find+0x1c/0x38 ixp46x_ptp_find from ixp4xx_get_ts_info+0x4c/0x64 ixp4xx_get_ts_info from __ethtool_get_ts_info+0x90/0x108 __ethtool_get_ts_info from __dev_ethtool+0xa00/0x2648 __dev_ethtool from dev_ethtool+0x160/0x234 dev_ethtool from dev_ioctl+0x2cc/0x460 dev_ioctl from sock_ioctl+0x1ec/0x524 sock_ioctl from sys_ioctl+0x51c/0xa94 sys_ioctl from ret_fast_syscall+0x0/0x44 (...) Segmentation fault Check for ixp46x in ixp46x_ptp_find() before trying to set up PTP to avoid this. To avoid altering the returned error code from ixp4xx_hwtstamp_set() which before this patch was -EOPNOTSUPP, we return -EOPNOTSUPP from ixp4xx_hwtstamp_set() if ixp46x_ptp_find() fails no matter the error code. The helper function ixp46x_ptp_find() helper returns -ENODEV.

Frequently asked questions

What is CVE-2026-43173?: In the Linux kernel, the following vulnerability has been resolved: net: ethernet: xscale: Check for PTP support properly In ixp4xx_get_ts_info() ixp46x_ptp_find() is called unconditionally despite this feature only existing on ixp46x, leading to the following splat from tcpdump: root@OpenWrt:~# tcpdump -vv -X -i eth0 (...) Unable to handle kernel NULL pointer dereference at virtual address 00000238 when read (...) Call trace: ptp_clock_index from ixp46x_ptp_find+0x1c/0x38 ixp46x_ptp_find from ixp4xx_get_ts_info+0x4c/0x64 ixp4xx_get_ts_info from __ethtool_get_ts_info+0x90/0x108 __ethtool_get_ts_info from __dev_ethtool+0xa00/0x2648 __dev_ethtool from dev_ethtool+0x160/0x234 dev_ethtool from dev_ioctl+0x2cc/0x460 dev_ioctl from sock_ioctl+0x1ec/0x524 sock_ioctl from sys_ioctl+0x51c/0xa94 sys_ioctl from ret_fast_syscall+0x0/0x44 (...) Segmentation fault Check for ixp46x in ixp46x_ptp_find() before trying to set up PTP to avoid this. To avoid altering the returned error code from ixp4xx_hwtstamp_set() which before this patch was -EOPNOTSUPP, we return -EOPNOTSUPP from ixp4xx_hwtstamp_set() if ixp46x_ptp_find() fails no matter the error code. The helper function ixp46x_ptp_find() helper returns -ENODEV.
How severe is CVE-2026-43173?: CVE-2026-43173 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-43173 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43173?: CVE-2026-43173 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-43173?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43173 have an EU (EUVD) identifier?: Yes. CVE-2026-43173 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27734.
When was CVE-2026-43173 published?: CVE-2026-43173 was published on 2026-05-06 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*

More vulnerabilities in Linux Linux Kernel

CVE-2023-2163 — Critical (CVSS 10.0): Incorrect verifier pruning in BPF in Linux Kernel >=5.4 leads to unsafe code paths being incorrectly marked as safe,…
CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
CVE-2015-1421 — Critical (CVSS 10.0): Use-after-free vulnerability in the sctp_assoc_update function in net/sctp/associola.c in the Linux kernel before…
CVE-2014-2523 — Critical (CVSS 10.0): net/netfilter/nf_conntrack_proto_dccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly,…
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2010-2521 — Critical (CVSS 10.0): Multiple buffer overflows in fs/nfsd/nfs4xdr.c in the XDR implementation in the NFS server in the Linux kernel before…

All CVEs affecting Linux Linux Kernel →

Other CWE-476 (NULL Pointer Dereference) vulnerabilities

CVE-2022-36648 — Critical (CVSS 10.0): The hardware emulation in the of_dpa_cmd_add_l2_flood of rocker device model in QEMU, as used in 7.0.0 and earlier,…
CVE-2020-14500 — Critical (CVSS 10.0): Secomea GateManager all versions prior to 9.2c, An attacker can send a negative value and overwrite arbitrary data.
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2026-46195 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building…
CVE-2026-31657 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by…
CVE-2026-31436 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix possible wrong descriptor…

Browse all CWE-476 (NULL Pointer Dereference) vulnerabilities →