CVE-2026-4873
connection reuse ignores TLS requirement
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-319 |
| Vendor | curl |
| Product | curl |
| Published | May 13, 2026 |
| Last Updated | Sep 15, 2026 |
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Affected Versions
curl / curl
7.20.0 < 8.14.2 8.15.0 < 8.16.1 8.17.0 < 8.20.0
curl / curl
ec3bb8f727405642a471b4b1b9eb0118fc003104 < 507e7be573b0a76fca597b75ff7cb27a66e7d865
curl / curl
8.19.0 8.18.0 8.17.0 8.16.0 8.15.0 8.14.1 8.14.0 8.13.0 8.12.1 8.12.0 8.11.1 8.11.0 8.10.1 8.10.0 8.9.1 8.9.0 8.8.0 8.7.1 8.7.0 8.6.0 8.5.0 8.4.0 8.3.0 8.2.1 8.2.0 8.1.2 8.1.1 8.1.0 8.0.1 8.0.0 7.88.1 7.88.0 7.87.0 7.86.0 7.85.0 7.84.0 7.83.1 7.83.0 7.82.0 7.81.0 7.80.0 7.79.1 7.79.0 7.78.0 7.77.0 7.76.1 7.76.0 7.75.0 7.74.0 7.73.0 7.72.0 7.71.1 7.71.0 7.70.0 7.69.1 7.69.0 7.68.0 7.67.0 7.66.0 7.65.3 7.65.2 7.65.1 7.65.0 7.64.1 7.64.0 7.63.0 7.62.0 7.61.1 7.61.0 7.60.0 7.59.0 7.58.0 7.57.0 7.56.1 7.56.0 7.55.1 7.55.0 7.54.1 7.54.0 7.53.1 7.53.0 7.52.1 7.52.0 7.51.0 7.50.3 7.50.2 7.50.1 7.50.0 7.49.1 7.49.0 7.48.0 7.47.1 7.47.0 7.46.0 7.45.0 7.44.0 7.43.0 7.42.1 7.42.0 7.41.0 7.40.0 7.39.0 7.38.0 7.37.1 7.37.0 7.36.0 7.35.0 7.34.0 7.33.0 7.32.0 7.31.0 7.30.0 7.29.0 7.28.1 7.28.0 7.27.0 7.26.0 7.25.0 7.24.0 7.23.1 7.23.0 7.22.0 7.21.7 7.21.6 7.21.5 7.21.4 7.21.3 7.21.2 7.21.1 7.21.0 7.20.1 7.20.0
References
Credits
Arkadi Vainbrand Daniel Stenberg