Red Hat Security Advisory: .NET 9.0 security, bug fix, and enhancement update
Affects Red Hat .NET 9.0Source GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 5.9 Medium · fixed in Red Hat package updates : update Red Hat microsoft.netcore.app when convenient.
Data as of 30 Oct 2026, 06:59 UTC
Thin evidence
One scorer or none| CNA (microsoft) | CVSS 3.1 | 5.9 |
|---|
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 10.0.11, 8.0.30, 9.0.19 +2
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 11 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft.NET 10.0 runtime | Affected
| Fixed in
|
| Microsoft.NET 8.0 runtime | Affected
| Fixed in
|
| Microsoft.NET 9.0 runtime | Affected
| Fixed in
|
| MicrosoftMicrosoft Visual Studio 2022 version 17.14 | Affected
| Fixed in
|
| MicrosoftMicrosoft Visual Studio 2026 version 18.8 | Affected
| Fixed in
|
NuGetmicrosoft.netcore.apppkg:nuget/microsoft.netcore.appOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released an official update that addresses these vulnerabilities by upgrading .NET to SDK version 9.0.120 and Runtime version 9.0.19. Users should apply this update promptly following Red Hat's published guidance at https://access.redhat.com/articles/11258 to remediate the security issues. No additional mitigation steps are indicated beyond applying the official patch.
Description
.NET 9.0 on Red Hat Enterprise Linux has multiple security vulnerabilities including security feature bypass, information disclosure, denial of service, and elevation of privilege. These issues are addressed in an update to SDK 9.0.120 and Runtime 9.0.19. The update is rated as having an Important security impact by Red Hat Product Security.
References
- access.redhat.com/errata/RHSA-2026:54590 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2512175 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2512179 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2512180 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2512185 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_54590.json (opens in a new tab)