CVE-2026-20639

An integer overflow was addressed with improved input validation. This issue is fixed in macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, macOS Tahoe 26.3. Processing a maliciously crafted string may lead to heap corruption.

Published: 2026-03-25 Last update: 2026-03-25 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20639 is rated Low Risk (35.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). 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-2026-20639

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 2026-03-31 0.02% 0.05% +0.03%
2 2026-03-25 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20639

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-20639

Affected software / configurations for CVE-2026-20639

Vendor Product Version Raw CPE
apple macos >= 14.0, < 14.8.5 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple macos >= 15.0, < 15.7.5 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple macos >= 26.0, < 26.3 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*

References for CVE-2026-20639

URL Tags
https://support.apple.com/en-us/126348 Release Notes Vendor Advisory
https://support.apple.com/en-us/126795 Release Notes Vendor Advisory
https://support.apple.com/en-us/126796 Release Notes Vendor Advisory
cvelogic Threat Intelligence