How severe is CVE-2019-1429?

CVE-2019-1429 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2019-1429?

Affected package information for CVE-2019-1429 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2019-1429?

No fixed version has been published for CVE-2019-1429 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2019-1429 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2019-1429, including 1 documented proof-of-concept exploit on Exploit-DB and 4 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2019-1429?

CVE-2019-1429 has an EPSS (Exploit Prediction Scoring System) score of 83.0%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2019-1429 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2019-1429 (Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2019-1429?

CVE-2019-1429 is classified as Use After Free (CWE-416), Out-of-bounds Write (CWE-787). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2019-1429?

CVE-2019-1429 affects microsoft internet explorer (3 versions, e.g. 9, 10, 11). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2019-1429 published, and has it been updated?

CVE-2019-1429 was published on November 12, 2019 and was last updated on January 14, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03

CVE-2019-1429

HIGH

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer, aka 'Scripting Engine Memory Corruption Vulnerability'.…

Published

Nov 12, 2019

Updated

Jan 14, 2026

Affected

0 pkgs

Patched

None yet

Exploits

5 known

EPSS Exploitation Probability

via FIRST.org ↗

83.0%probability of exploitation in next 30 days

Very High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer, aka 'Scripting Engine Memory Corruption Vulnerability'. This CVE ID is unique from CVE-2019-1426, CVE-2019-1427, CVE-2019-1428.

Affected Products

1 product · 3 configurations

Application

internet explorermicrosoft

3 versions

91011

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-47707doswindows✓ Verified

Internet Explorer - Use-After-Free in JScript Arguments During toJSON Callback

by Google Security Research · Nov 22, 2019

Exploit-DB Source

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2019-1429 in your stack?

O3 detects CVE-2019-1429 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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