NVD / CVE Program· CNA Linux

CVE-2026-63837: net: ena: PHC: Check return code before setting timestamp output

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 24a08d7d6218d60c033015cf4870b6096446e734, bddf59818ae5102e6d82a4dae5add6df8da38fb0, edcb049d836e175e7b3d5e0d05657104545b5e65.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 24a08d7d6218d60c033015cf4870b6096446e734, bddf59818ae5102e6d82a4dae5add6df8da38fb0, edcb049d836e175e7b3d5e0d05657104545b5e65 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: net: ena: PHC: Check return code before setting timestamp output ena_phc_gettimex64() is setting the output parameter regardless of whether ena_com_phc_get_timestamp() succeeded or failed. When ena_com_phc_get_timestamp() returns an error, the timestamp parameter may contain uninitialized stack memory (e.g., when PHC is disabled or in blocked state) or invalid hardware values. Passing these to userspace via the PTP ioctl is both a security issue (information leak) and a correctness bug. Fix by checking the return code after releasing the lock and only setting the output timestamp on success.

Denial of service

Published: Jul 19, 2026
Updated: Nov 12, 2026
EPSS: 0.2% · 10th percentile
CWE: CWE-667

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 6.17affected
- e0ea34158ee8c4f7536cd781010339ff28c0d24c and later · before bddf59818ae5102e6d82a4dae5add6df8da38fb0affected · git
- e0ea34158ee8c4f7536cd781010339ff28c0d24c and later · before edcb049d836e175e7b3d5e0d05657104545b5e65affected · git
- e0ea34158ee8c4f7536cd781010339ff28c0d24c and later · before 24a08d7d6218d60c033015cf4870b6096446e734affected · git
- before 6.17not affected · semver
- 6.18.33 and later · up to and including 6.18.*not affected · semver
- 7.0.10 and later · up to and including 7.0.*not affected · semver
- 7.1 and laternot affected · original_commit_for_fix

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel6.17 and later · before 6.18.33
linux linux kernel6.19 and later · before 7.0.10
linux linux kernel7.1

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:14	linux	before 7.0.10-1	7.0.10-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

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Published before and after this one in the same product

← EarlierCVE-2026-64180Jul 19, 2026 · mm/memory_hotplug: fix memory block reference leak on remove
22Monitor
← EarlierCVE-2026-64181Jul 19, 2026 · mm: fix __vm_normal_page() to handle missing support for pmd_special()/pud_special()
31Monitor
Later →CVE-2026-63838Jul 19, 2026 · ASoC: rsnd: Fix potential out-of-bounds access of component_dais[]
28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	24a08d7d6218d60c033015cf4870b6096446e734	Vendor (CNA)
Linux Linux	bddf59818ae5102e6d82a4dae5add6df8da38fb0	Vendor (CNA)
Linux Linux	edcb049d836e175e7b3d5e0d05657104545b5e65	Vendor (CNA)
debian:linux	7.0.10-1 · Debian:14	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.