CVE-2026-4873
Last modified
CVE-2026-4873 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.. EPSS estimates a 0.33% chance of exploitation in the next 30 days.
Description
A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.
Metrics
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Haxx | Curl | >= 7.20.0, < 8.20.0 |
References
- https://curl.se/docs/CVE-2026-4873.htmlPatch, Vendor Advisory
- https://curl.se/docs/CVE-2026-4873.jsonVendor Advisory
- https://hackerone.com/reports/3621851Exploit, Issue Tracking, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2026/04/29/7Mailing List, Patch, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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