🔐 CVE Alert

CVE-2026-11856

CRITICAL 9.8

cross-origin Digest auth state leak

CVSS Score
9.8
EPSS Score
0.0%
EPSS Percentile
0th

Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest** authentication and then changing the origin to a different one (`hostB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Authorization:` header field meant for `hostA`, to `hostB`.

CWE CWE-294
Vendor curl
Product curl
Published Jul 3, 2026
Last Updated Sep 15, 2026
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Affected Versions

curl / curl
7.10.6 < 8.14.2 8.15.0 < 8.16.1 8.17.0 < 8.20.1
curl / curl
334d78cd18a7310144383929bdcef34ffbf6159b < 5c6b4880357ab3e72967c1c45cae0f96ffabc535
curl / curl
8.20.0 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 7.19.7 7.19.6 7.19.5 7.19.4 7.19.3 7.19.2 7.19.1 7.19.0 7.18.2 7.18.1 7.18.0 7.17.1 7.17.0 7.16.4 7.16.3 7.16.2 7.16.1 7.16.0 7.15.5 7.15.4 7.15.3 7.15.2 7.15.1 7.15.0 7.14.1 7.14.0 7.13.2 7.13.1 7.13.0 7.12.3 7.12.2 7.12.1 7.12.0 7.11.2 7.11.1 7.11.0 7.10.8 7.10.7 7.10.6

References

NVD ↗ CVE.org ↗ EPSS Data ↗
curl.se: https://curl.se/docs/CVE-2026-11856.json curl.se: https://curl.se/docs/CVE-2026-11856.html hackerone.com: https://hackerone.com/reports/3793260

Credits

jjchuck on hackerone Daniel Stenberg