CVE-2026-19931
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when the initial request is done using empty credentials. This can make user B's request get sent over user A's previously authenticated connection.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| curl | curl | 7.64.1 < 8.14.2 | affected |
| curl | curl | 8.15.0 < 8.16.1 | affected |
| curl | curl | 8.17.0 < 8.20.1 | affected |
| curl | curl | 8.21.0 < 8.22.0 | affected |
| curl | curl | 6c6035532383e300c712e4c1cd9fdd749ed5cf59 < 7103a93b05bc69ea98ed9d05d02fa9eeba533f2f | affected |
| curl | curl | 8.21.0 | affected |
| curl | curl | 8.20.0 | affected |
| curl | curl | 8.19.0 | affected |
| curl | curl | 8.18.0 | affected |
| curl | curl | 8.17.0 | affected |
| curl | curl | 8.16.0 | affected |
| curl | curl | 8.15.0 | affected |
| curl | curl | 8.14.1 | affected |
| curl | curl | 8.14.0 | affected |
| curl | curl | 8.13.0 | affected |
| curl | curl | 8.12.1 | affected |
| curl | curl | 8.12.0 | affected |
| curl | curl | 8.11.1 | affected |
| curl | curl | 8.11.0 | affected |
| curl | curl | 8.10.1 | affected |
| curl | curl | 8.10.0 | affected |
| curl | curl | 8.9.1 | affected |
| curl | curl | 8.9.0 | affected |
| curl | curl | 8.8.0 | affected |
| curl | curl | 8.7.1 | affected |
| curl | curl | 8.7.0 | affected |
| curl | curl | 8.6.0 | affected |
| curl | curl | 8.5.0 | affected |
| curl | curl | 8.4.0 | affected |
| curl | curl | 8.3.0 | affected |
| curl | curl | 8.2.1 | affected |
| curl | curl | 8.2.0 | affected |
| curl | curl | 8.1.2 | affected |
| curl | curl | 8.1.1 | affected |
| curl | curl | 8.1.0 | affected |
| curl | curl | 8.0.1 | affected |
| curl | curl | 8.0.0 | affected |
| curl | curl | 7.88.1 | affected |
| curl | curl | 7.88.0 | affected |
| curl | curl | 7.87.0 | affected |
| curl | curl | 7.86.0 | affected |
| curl | curl | 7.85.0 | affected |
| curl | curl | 7.84.0 | affected |
| curl | curl | 7.83.1 | affected |
| curl | curl | 7.83.0 | affected |
| curl | curl | 7.82.0 | affected |
| curl | curl | 7.81.0 | affected |
| curl | curl | 7.80.0 | affected |
| curl | curl | 7.79.1 | affected |
| curl | curl | 7.79.0 | affected |
| curl | curl | 7.78.0 | affected |
| curl | curl | 7.77.0 | affected |
| curl | curl | 7.76.1 | affected |
| curl | curl | 7.76.0 | affected |
| curl | curl | 7.75.0 | affected |
| curl | curl | 7.74.0 | affected |
| curl | curl | 7.73.0 | affected |
| curl | curl | 7.72.0 | affected |
| curl | curl | 7.71.1 | affected |
| curl | curl | 7.71.0 | affected |
| curl | curl | 7.70.0 | affected |
| curl | curl | 7.69.1 | affected |
| curl | curl | 7.69.0 | affected |
| curl | curl | 7.68.0 | affected |
| curl | curl | 7.67.0 | affected |
| curl | curl | 7.66.0 | affected |
| curl | curl | 7.65.3 | affected |
| curl | curl | 7.65.2 | affected |
| curl | curl | 7.65.1 | affected |
| curl | curl | 7.65.0 | affected |
| curl | curl | 7.64.1 | affected |
Weaknesses
- CWE-488: Exposure of Data Element to Wrong Session
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: poc
- Automatable: yes
- Technical Impact: total
Additional References
References
- https://curl.se/docs/CVE-2026-19931.json
- https://curl.se/docs/CVE-2026-19931.html
- https://hackerone.com/reports/3923520
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