Improper Certificate Validation The advisory has been revoked - it doesn't affect any version of package curl (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UBUNTU1804-CURL-16335654
- published1 May 2026
- disclosed13 May 2026
Introduced: 1 May 2026
CVE-2026-4873 (opens in a new tab)Amendment
The Ubuntu security team deemed this advisory irrelevant for Ubuntu:18.04.
NVD Description
Note: Versions mentioned in the description apply only to the upstream curl package and not the curl package as distributed by Ubuntu.
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.