Actively exploited · Published Mar 11, 2021 · Assigned by microsoft
CVE-2021-26411Internet Explorer Memory Corruption Vulnerability
High 8.8 Exploited Ransomware
In plain English
A high-severity use-after-free in Internet Explorer 11 from Microsoft. Attackers are actively exploiting it in the wild (listed by CISA on November 3, 2021). It has been used in ransomware campaigns. The chance it is exploited in the next 30 days is estimated at 81.7% (higher than 99.6% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Apply updates per vendor instructions.
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)81.7%top 0.4% of all CVEs
Exploited in the wildYesCISA KEV since Nov 3, 2021
Attack tooling1Public PoC
CISA guidance
Apply updates per vendor instructions.
Federal agencies must remediate by Nov 17, 2021.
Official description
Internet Explorer Memory Corruption Vulnerability
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Internet Explorer 11 | 1.0.0 – before 10.0.17134.2087 |
| Microsoft | Internet Explorer 9 | 1.0.0 – before 6.0.6003.21070 |
| Microsoft | Microsoft Edge (EdgeHTML-based) | 1.0..0 – before 10.0.17134.2087 |
Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:C
References
- Internet Explorer Memory Corruption Vulnerability vendor-advisory, patch
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26411 x_refsource_MISC, x_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26411 government-resource