CVE-2026-38755: A heap overflow in the evalcommand() function (shell/ash.c) of Busybox v1.38.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted input.

highCVSS 7.5CVE-2026-38755

CSIRTS triage

vendor: Busybox product: Busybox Denial of serviceaffected: v1.38.0

What: A heap overflow in the evalcommand() function allows attackers to cause a Denial of Service (DoS) via crafted input.
Who is affected: Users of Busybox v1.38.0 are affected by this vulnerability.
Urgency: Remediation is urgent due to the high severity and potential for DoS attacks.
Action: Upgrade to a patched version of Busybox 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 7.5
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-38755

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-2026-387550.21% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 11% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-38755	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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