CVE-2026-62898
published 2026-08-11CVE-2026-62898: Use after free in Microsoft QUIC allows an unauthorized attacker to disclose information over a network.
PriorityP349high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
1.11%
63.4th percentile
Use after free in Microsoft QUIC allows an unauthorized attacker to disclose information over a network.
Affected
19 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | microsoft.netcore.app.runtime.win-arm64 | >= 10.0.0 < 10.0.11 | 10.0.11 |
| microsoft | microsoft.netcore.app.runtime.win-arm64 | >= 8.0.0 < 8.0.30 | 8.0.30 |
| microsoft | microsoft.netcore.app.runtime.win-arm64 | >= 9.0.0 < 9.0.19 | 9.0.19 |
| microsoft | microsoft.netcore.app.runtime.win-x64 | >= 10.0.0 < 10.0.11 | 10.0.11 |
| microsoft | microsoft.netcore.app.runtime.win-x64 | >= 8.0.0 < 8.0.30 | 8.0.30 |
| microsoft | microsoft.netcore.app.runtime.win-x64 | >= 9.0.0 < 9.0.19 | 9.0.19 |
| microsoft | microsoft.netcore.app.runtime.win-x86 | >= 10.0.0 < 10.0.11 | 10.0.11 |
| microsoft | microsoft.netcore.app.runtime.win-x86 | >= 8.0.0 < 8.0.30 | 8.0.30 |
| microsoft | microsoft.netcore.app.runtime.win-x86 | >= 9.0.0 < 9.0.19 | 9.0.19 |
| microsoft | microsoft_visual_studio_2022_version_17.14 | >= 17.14.0 < 17.14.38 | 17.14.38 |
| microsoft | microsoft_visual_studio_2026_version_18.8 | >= 18.0 < 18.8.3 | 18.8.3 |
| microsoft | net | >= 10.0.0 < 10.0.11 | 10.0.11 |
| microsoft | net | >= 8.0.0 < 8.0.30 | 8.0.30 |
| microsoft | net | >= 9.0.0 < 9.0.19 | 9.0.19 |
| microsoft | net_10.0 | >= 10.0.0 < 10.0.11 | 10.0.11 |
| microsoft | net_8.0 | >= 8.0.0 < 8.0.30 | 8.0.30 |
| microsoft | net_9.0 | >= 9.0.0 < 9.0.19 | 9.0.19 |
| microsoft | visual_studio_2022 | >= 17.14.0 < 17.14.38 | 17.14.38 |
| microsoft | visual_studio_2026 | >= 18.8.0 < 18.8.3 | 18.8.3 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
ghsa7.5HIGH
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
VulDB
Microsoft .NET/Visual Studio QUIC use after free (EUVD-2026-56773)
vuldb·2026-08-12·CVSS 7.5
CVE-2026-62898 [HIGH] Microsoft .NET/Visual Studio QUIC use after free (EUVD-2026-56773)
A vulnerability categorized as critical has been discovered in Microsoft .NET and Visual Studio. Affected by this vulnerability is an unknown functionality of the component QUIC. Executing a manipulation can lead to use after free.
The identification of this vulnerability is CVE-2026-62898. The attack may be launched remotely. There is no exploit available.
It is advisable to implement a patch to correct this issue.
GHSA
Microsoft Security Advisory CVE-2026-62898 – .NET Information Disclosure Vulnerability
ghsa·2026-08-11·CVSS 7.5
CVE-2026-62898 [HIGH] CWE-416 Microsoft Security Advisory CVE-2026-62898 – .NET Information Disclosure Vulnerability
Microsoft Security Advisory CVE-2026-62898 – .NET Information Disclosure Vulnerability
## Executive summary
Microsoft is releasing this security advisory to provide information about a vulnerability in Microsoft QUIC. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
A use after free in Microsoft QUIC allows an unauthorized attacker to disclose information over a network.
## Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/426
## CVSS Details
- **Version:** 3.1
- **Severity:** High
- **Score:** 7.5
- **Vector:** `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C`
- **Weakness:** CWE-416: Use After Free
## Affected Platforms
- **Platforms:** Window
No detection rules found.
No public exploits indexed.
Rapid7
Patch Tuesday - August 2026
blogs_rapid7·2026-08-11·CVSS 7.2
CVE-2026-68821 [HIGH] Patch Tuesday - August 2026
Microsoft is publishing 421 vulnerabilities on August 2026 Patch Tuesday , including 236 vulnerabilities in Windows. This is lower volume than last month’s record-breaking behemoth, but still one of the largest Patch Tuesday totals ever. There is no reason to suppose that Patch Tuesday will ever return to the lower volumes we saw prior to 2026. Microsoft is aware of exploitation in the wild for one of the vulnerabilities published today, as well as public disclosure for two others, although the Notable CVEs section of the Security Update Guide omits one of these. As usual, browser vulns are not included in the Patch Tuesday count above, but unusually, Microsoft does not appear to have published any desktop browser security patches so far this month.
## Summary charts
## Summary tables
#
Sans Isc
Microsoft Patch Tuesday August 2026, (Tue, Aug 11th)
blogs_sans_isc·2026-08-11·CVSS 7.8
CVE-2026-68820 [HIGH] Microsoft Patch Tuesday August 2026, (Tue, Aug 11th)
Microsoft Patch Tuesday August 2026
Published: 2026-08-11. Last Updated: 2026-08-11 17:54:49 UTC
by Renato Marinho (Version: 1)
0 comment(s)
This month we got patches for 418 vulnerabilities. Of these, 62 are critical, 1 is being exploited in the wild, and 2 were publicly disclosed as zero-days. Notable fixes include Windows privilege escalation, container tampering, and critical QUIC and DNS Server remote code execution bugs.
A few vulnerabilities worth mentioning:
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability (CVE-2026-68820)
This Important-severity elevation of privilege vulnerability is listed by Microsoft as exploited in the wild but not publicly disclosed, and it has a CVSS score of 7.0. The flaw is a use-after-free issue in the Windows Ancil
2026-08-11
Published