auto client cert connection reuse mixup

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-86415
StatePUBLISHED
Assignercurl
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-20 21:17:20 UTC
Updated2026-10-30 12:16:45 UTC
Descriptionlibcurl's connection cache match function never considers the automatic client certificate option, so a cached, already authenticated Schannel connection can be handed to a transfer that got redirected to a different origin, even though the code explicitly switched off the auto client cert option for that transfer to prevent exactly this.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from ADP

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

EPSS: 0.002160000 probability, percentile 0.120600000 (date 2026-10-30)

Problem Types: CWE-201 | CWE-201 Information Exposure Through Sent Data | CWE-201 CWE-201 Insertion of Sensitive Information Into Sent Data

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Curl Curl affected 8.22.0 8.22.0 semver Not specified
CNA Curl Curl affected 8.21.0 8.21.0 semver Not specified

References

ReferenceSourceLinkTags
hackerone.com/reports/3993870 2499f714-1537-4658-8207-48ae4bb9eae9 hackerone.com
curl.se/docs/CVE-2026-86415.html 2499f714-1537-4658-8207-48ae4bb9eae9 curl.se
curl.se/docs/CVE-2026-86415.json 2499f714-1537-4658-8207-48ae4bb9eae9 curl.se
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Stanislav Fort (Aisle Research) (en)

CNA: Stefan Eissing (en)

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