CVE-2026-4873: curl · Cleartext Transmission
Affects curlSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 11 Nov 2026, 23:18 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 5.9 |
|---|
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| curl curl | Affected
| Fixed in– |
AI-suggested
Until a fix is available, avoid reusing connection pools for protocols requiring TLS or configure curl to enforce TLS strictly for each connection. Monitor vendor communications for updates.
Description
CVE-2026-4873 is a medium severity vulnerability in curl where a connection that should use TLS incorrectly reuses an existing unencrypted connection from the same connection pool. This causes subsequent requests to the same host to bypass TLS and transmit sensitive data in cleartext, affecting protocols like IMAP, SMTP, and POP3.