FTP connection reuse inherits client-certificate
Severity and exploitation
KEV coverage does not rule out exploitation.
Assessment vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NSeverity
critical9.1CVSS measures technical severity, not the likelihood of an attack.
Known exploitation
Not listed in the checked CISA KEV catalog
Absence from CISA KEV does not rule out attacks.
Public exploit
Exploit reference published
Source-linked evidence; not proof of attacks in the wild or independent validation.
Remediation
Fix status not established
No structured fix or guidance is available here. Check the latest publisher advisory.
What this means
An ftp:// transfer configured with CURLUSESSL_NONE can reuse a pooled FTP control connection that a previous easy handle upgraded with STARTTLS and authenticated using a client certificate. The second handle performs neither a new TLS handshake nor a new FTP login, so the server continues to authorize it under the first handle's certificate identity.
Source excerpt · curlAttack conditions
No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.
Review supporting sources →Affected versions
Check the exact model, release, and any platform requirements against your installation.
curl · curl
curl
1 range
curl · curl
curl
Compare with this publisher’s ranges. This does not inspect your installation.
affected
8.21.0 → through 8.21.0
semver versions
Other versions: unaffected
What to do
Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.
No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.
cve.new guidance unless attributed to a publisher. This page does not inspect your installation.
Public exploit evidence
The sources identify public exploit references. We have not independently tested them; their availability does not establish exploitation in the wild.
hackerone.com/reports/3973190 ↗Attributed to CISA-ADPOriginal source description
Read the full publisher description
An ftp:// transfer configured with CURLUSESSL_NONE can reuse a pooled FTP
control connection that a previous easy handle upgraded with STARTTLS and
authenticated using a client certificate. The second handle performs neither a
new TLS handshake nor a new FTP login, so the server continues to authorize it
under the first handle's certificate identity.
References
3 sourcesInside the record
Evidence available
Describes the evidence in this view, not whether the product is safe.
Original records
CVE-2026-86411View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Underlying weaknesses
The source’s classification of what caused the vulnerability.
Contributing organizations · 2
Assigning organization
Additional data publisher
Timeline
All times UTCAdvisory published
Publication date supplied by the source.
Source updated
Latest modification date supplied by the source.
Last imported by cve.new
Latest catalog import, not the date we first saw this advisory.
What changed
Follow changesLarge field values are marked as truncated previews. Original source snapshots remain retained.