CVE-2019-8721

Multiple issues in ld64 in the Xcode toolchains were addressed by updating to version ld64-507.4. This issue is fixed in Xcode 11.0. Compiling code without proper input validation could lead to arbitrary code execution with user privilege.

Published: 2019-12-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-8721 is rated Moderate Risk (62.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.79%). EPSS rose +1.19% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

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-2019-8721

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 2026-06-15 0.60% 1.79% +1.19%
2 2025-03-30 1.78% 0.60% -1.18%
3 2025-03-29 — 1.78% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-8721

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 10.0 [email protected]

Weakness enumeration for CVE-2019-8721

Affected software / configurations for CVE-2019-8721

Vendor Product Version Raw CPE
apple xcode < 11.0 cpe:2.3:a:apple:xcode:*:*:*:*:*:*:*:*

References for CVE-2019-8721

URL Tags
https://support.apple.com/HT210609 Vendor Advisory
cvelogic Threat Intelligence