CVE-2021-26411
Microsoft Internet Explorer Memory Corruption Vulnerability
CVSS
8.8
High
EPSS
80.8%
p100
KEV
YES
Nov 3, 2021
Exploit Today
80
0-100
Published: Mar 11, 2021 · Last modified: Aug 19, 2026 · CWE-416
80.7%EPSS · 30 days80.8%
2026-08-022026-08-31
Product
Microsoft / Internet Explorer
Vulnerability
Microsoft Internet Explorer Memory Corruption Vulnerability
Added to KEV
Nov 3, 2021
Remediate by
Nov 17, 2021
Known ransomware use
Yes
Summary description
Microsoft Internet Explorer contains an unspecified vulnerability that allows for memory corruption.
Required action
Apply updates per vendor instructions.
Notes
https://nvd.nist.gov/vuln/detail/CVE-2021-26411
Internet Explorer Memory Corruption Vulnerability
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-826312.2 LOW28.8%
——9A security flaw has been discovered in valkey-io valkey 9.1.0. The affected element is the function handleClientsBlockedOnKey of the file src/blocked.c of the component Blocked-on-keys Subsystem. The manipulation results in use after free. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is described as difficult. The exploit has been released to the public and may be used for attacks. The patch is identified as b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b. Applying a patch is advised to resolve this issue.2hCVE-2026-826235.3 MED33.6%
——10A vulnerability was detected in open62541 up to 1.5.5. Affected by this vulnerability is the function UA_DataValue_backend_copyRange of the file plugins/historydata/ua_history_data_backend_memory.c of the component History Backend. The manipulation results in use after free. The attack can be launched remotely. The exploit is now public and may be used. The project closed the issue report, stating that this is not the official way to report a security vulnerability.7hCVE-2026-826194.3 MED22.4%
——7A vulnerability was identified in Systerel S2OPC up to 1.7.3. The impacted element is the function monitored_item_event_filter_treatment_bs__init_event_filter_ctx_and_result of the file src/ClientServer/services/bgenc/subscription_mgr.c. Such manipulation of the argument EventFilter leads to use after free. The attack may be performed from remote. The exploit is publicly available and might be used. The name of the patch is a4cee16a851b971be447a6ed531173702c722b99. It is best practice to apply a patch to resolve this issue.8hCVE-2026-667984.3 MED44.8%
——13Use after free in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.2dCVE-2026-420079.1 CRI20.9%
——6An attacker that has valid credentials can use a Sieve script with the editheader extension to trigger a use-after-free in the mail editing code, and to write memory contents beyond the intended buffer into the delivered mail. This causes memory leak and opportunity to do memory corruption during mail delivery, which can crash the delivery process and may allow execution of arbitrary code in the context of that process. Disable the Sieve editheader extension. Update to non-vulnerable version. No publicly available exploits are known.3dCVE-2026-19316—24.6%
——7A double-free vulnerability in the WatchGuard Fireware OS iked process allows a remote unauthenticated attacker to create a Denial of Service (DoS) condition in VPN processing by sending specially crafted network traffic.3d