CVE-2026-63808: exfat: fix potential use-after-free in exfat_find_dir_entry()

highCVSS 7.1CVE-2026-63808

CSIRTS triage

product: exfatOther

What: A potential use-after-free vulnerability has been found in the exfat_find_dir_entry() function.
Who is affected: Deployments using the exfat file system may be affected.
Urgency: Remediation is important as the severity is currently unknown.
Action: Apply the latest updates for exfat to mitigate this vulnerability.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.1
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63808

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-638080.50% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 40% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-63808	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for exfat

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-64296: In the Linux kernel, the following vulnerability has been resolved: exfat: bound uniname advan…nvd · 2026-07-25
criticalCVE-2026-63808: In the Linux kernel, the following vulnerability has been resolved: exfat: fix potential use-a…nvd · 2026-07-19
highCVE-2026-64296: exfat: bound uniname advance in exfat_find_dir_entry()msrc · 2026-07-14
highCVE-2026-6687: FatFs R0.16 and earlier contains a stack overflow bug in f_getlabel() because exFAT label lengt…nvd · 2026-07-01
mediumCVE-2026-6683: FatFs R0.16 and earlier contains a divide-by-zero in exFAT sync logic bug when crafted metadata…nvd · 2026-07-01