Vulnerability details
CVE-2026-87861
curl curl
cross-origin reuse of a Negotiate connection
CVSS 3.1
9.1Critical
Official description
When using ambient user credentials, an HTTP request directed to one origin may be dispatched over a connection previously authenticated via Negotiate for a different origin, leaving the request's intended credentials unused.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.1Critical | 3.1 | CISA ADP / Vulnrichment (CISA-ADP) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| curl | curl | 8.21.0 ≤ v ≤ 8.21.0 | CVEProject cvelistV5 (CNA) |
| curl | curl | 8.22.0 ≤ v ≤ 8.22.0 | CVEProject cvelistV5 (CNA) |
References and advisories
3
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Details
- Published
- 2026-10-20
- Last updated
- 2026-10-30
- State
- Published
- Assigner (CNA)
- curl
- Kolun priority
- 27 · Low
Exploit prediction (EPSS)
0.67%
Probability of exploitation in 30 days
52.5%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- Proof of concept
- Technical impact
- Total
Weaknesses (CWE)
- CWE-201Insertion of Sensitive Information Into Sent Data