CVE-2026-62899
MEDIUM 5.9Inconsistent interpretation of http requests ('http request/response smuggling') in .NET allows an unauthorized attacker to bypass a security feature over a network.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.7%chance of exploitation in 30 days · 51st percentile
Impact if exploited
5.9CVSS 3.1 · MEDIUM
- ConfidentialityHigh
- IntegrityNone
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ⚠Complexity: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-62899/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-62899/poc.json
Affected
Products .Net 10.0 .Net 8.0 .Net 9.0 Microsoft Visual Studio 2022 Version 17.14 Microsoft Visual Studio 2026 Version 18.8 Visual Studio 2022 Visual Studio 2026 .Net Macos Linux Kernel Windows
Weakness (CWE)
- CWE-444: : Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | Visual Studio 2022 | ≥ 17.14.0 and < 17.14.38 |
| Microsoft | Visual Studio 2026 | ≥ 18.8.0 and < 18.8.3 |
| Microsoft | .Net | ≥ 8.0.0 and < 8.0.30 |
| Microsoft | .Net | ≥ 9.0.0 and < 9.0.19 |
| Microsoft | .Net | ≥ 10.0.0 and < 10.0.11 |
All CVSS metrics
- MEDIUM 5.9 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C - MEDIUM 5.9 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N