8.1High

CVE-2026-8286wrong STARTTLS connection reuse

curl curl Published: 2026-07-03 09:14 (4 months ago)

Description

A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not.

Weakness (CWE): CWE-295

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

Vendor	Product	Versions
curl	curl	7.30.0 – < 8.14.2, 8.15.0 – < 8.16.1, 8.17.0 – < 8.20.1
haxx	curl	7.30.0 – < 8.21.0

References and patches

https://curl.se/docs/CVE-2026-8286.json Vendor Advisory
https://curl.se/docs/CVE-2026-8286.html PatchVendor Advisory
https://hackerone.com/reports/3718195 ExploitIssue TrackingThird Party Advisory

CPE matches (NVD) (1)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* ≥ 7.30.0 < 8.21.0

CVSS score

8.1High

Source: CISA-ADP · CVSS 3.1

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

All scores (2)

CISA-ADP	CVSS 3.1	8.1High
134c704f-9b21-4f2e-91b3-4a467353bcc0	CVSS 3.1	8.1High

EPSS (chance of exploitation in 30 days)

0.31%

higher than 24% of all CVEs

CISA assessment (SSVC)

Exploitation: poc
Automatable: no
Technical impact: total

Timeline

ID reserved2026-05-11
Published2026-07-03 09:14
Reached IP-DB2026-10-24 23:40
Last updated2026-09-15 10:16

Assigned by (CNA): curl
NVD status: Modified

View at source: CVE.org · NVD

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