🔐 CVE Alert

CVE-2026-11856

CRITICAL 9.8

cross-origin Digest auth state leak

CVSS Score
9.8
EPSS Score
0.3%
EPSS Percentile
16th

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`.

Vendor curl
Product curl
Published Jul 3, 2026
Last Updated Jul 6, 2026
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Affected Versions

curl / curl
8.20.0 ≤ 8.20.0 8.19.0 ≤ 8.19.0 8.18.0 ≤ 8.18.0 8.17.0 ≤ 8.17.0 8.16.0 ≤ 8.16.0 8.15.0 ≤ 8.15.0 8.14.1 ≤ 8.14.1 8.14.0 ≤ 8.14.0 8.13.0 ≤ 8.13.0 8.12.1 ≤ 8.12.1 8.12.0 ≤ 8.12.0 8.11.1 ≤ 8.11.1 8.11.0 ≤ 8.11.0 8.10.1 ≤ 8.10.1 8.10.0 ≤ 8.10.0 8.9.1 ≤ 8.9.1 8.9.0 ≤ 8.9.0 8.8.0 ≤ 8.8.0 8.7.1 ≤ 8.7.1 8.7.0 ≤ 8.7.0 8.6.0 ≤ 8.6.0 8.5.0 ≤ 8.5.0 8.4.0 ≤ 8.4.0 8.3.0 ≤ 8.3.0 8.2.1 ≤ 8.2.1 8.2.0 ≤ 8.2.0 8.1.2 ≤ 8.1.2 8.1.1 ≤ 8.1.1 8.1.0 ≤ 8.1.0 8.0.1 ≤ 8.0.1 8.0.0 ≤ 8.0.0 7.88.1 ≤ 7.88.1 7.88.0 ≤ 7.88.0 7.87.0 ≤ 7.87.0 7.86.0 ≤ 7.86.0 7.85.0 ≤ 7.85.0 7.84.0 ≤ 7.84.0 7.83.1 ≤ 7.83.1 7.83.0 ≤ 7.83.0 7.82.0 ≤ 7.82.0 7.81.0 ≤ 7.81.0 7.80.0 ≤ 7.80.0 7.79.1 ≤ 7.79.1 7.79.0 ≤ 7.79.0 7.78.0 ≤ 7.78.0 7.77.0 ≤ 7.77.0 7.76.1 ≤ 7.76.1 7.76.0 ≤ 7.76.0 7.75.0 ≤ 7.75.0 7.74.0 ≤ 7.74.0 7.73.0 ≤ 7.73.0 7.72.0 ≤ 7.72.0 7.71.1 ≤ 7.71.1 7.71.0 ≤ 7.71.0 7.70.0 ≤ 7.70.0 7.69.1 ≤ 7.69.1 7.69.0 ≤ 7.69.0 7.68.0 ≤ 7.68.0 7.67.0 ≤ 7.67.0 7.66.0 ≤ 7.66.0 7.65.3 ≤ 7.65.3 7.65.2 ≤ 7.65.2 7.65.1 ≤ 7.65.1 7.65.0 ≤ 7.65.0 7.64.1 ≤ 7.64.1 7.64.0 ≤ 7.64.0 7.63.0 ≤ 7.63.0 7.62.0 ≤ 7.62.0 7.61.1 ≤ 7.61.1 7.61.0 ≤ 7.61.0 7.60.0 ≤ 7.60.0 7.59.0 ≤ 7.59.0 7.58.0 ≤ 7.58.0 7.57.0 ≤ 7.57.0 7.56.1 ≤ 7.56.1 7.56.0 ≤ 7.56.0 7.55.1 ≤ 7.55.1 7.55.0 ≤ 7.55.0 7.54.1 ≤ 7.54.1 7.54.0 ≤ 7.54.0 7.53.1 ≤ 7.53.1 7.53.0 ≤ 7.53.0 7.52.1 ≤ 7.52.1 7.52.0 ≤ 7.52.0 7.51.0 ≤ 7.51.0 7.50.3 ≤ 7.50.3 7.50.2 ≤ 7.50.2 7.50.1 ≤ 7.50.1 7.50.0 ≤ 7.50.0 7.49.1 ≤ 7.49.1 7.49.0 ≤ 7.49.0 7.48.0 ≤ 7.48.0 7.47.1 ≤ 7.47.1 7.47.0 ≤ 7.47.0 7.46.0 ≤ 7.46.0 7.45.0 ≤ 7.45.0 7.44.0 ≤ 7.44.0 7.43.0 ≤ 7.43.0 7.42.1 ≤ 7.42.1 7.42.0 ≤ 7.42.0 7.41.0 ≤ 7.41.0 7.40.0 ≤ 7.40.0 7.39.0 ≤ 7.39.0 7.38.0 ≤ 7.38.0 7.37.1 ≤ 7.37.1 7.37.0 ≤ 7.37.0 7.36.0 ≤ 7.36.0 7.35.0 ≤ 7.35.0 7.34.0 ≤ 7.34.0 7.33.0 ≤ 7.33.0 7.32.0 ≤ 7.32.0 7.31.0 ≤ 7.31.0 7.30.0 ≤ 7.30.0 7.29.0 ≤ 7.29.0 7.28.1 ≤ 7.28.1 7.28.0 ≤ 7.28.0 7.27.0 ≤ 7.27.0 7.26.0 ≤ 7.26.0 7.25.0 ≤ 7.25.0 7.24.0 ≤ 7.24.0 7.23.1 ≤ 7.23.1 7.23.0 ≤ 7.23.0 7.22.0 ≤ 7.22.0 7.21.7 ≤ 7.21.7 7.21.6 ≤ 7.21.6 7.21.5 ≤ 7.21.5 7.21.4 ≤ 7.21.4 7.21.3 ≤ 7.21.3 7.21.2 ≤ 7.21.2 7.21.1 ≤ 7.21.1 7.21.0 ≤ 7.21.0 7.20.1 ≤ 7.20.1 7.20.0 ≤ 7.20.0 7.19.7 ≤ 7.19.7 7.19.6 ≤ 7.19.6 7.19.5 ≤ 7.19.5 7.19.4 ≤ 7.19.4 7.19.3 ≤ 7.19.3 7.19.2 ≤ 7.19.2 7.19.1 ≤ 7.19.1 7.19.0 ≤ 7.19.0 7.18.2 ≤ 7.18.2 7.18.1 ≤ 7.18.1 7.18.0 ≤ 7.18.0 7.17.1 ≤ 7.17.1 7.17.0 ≤ 7.17.0 7.16.4 ≤ 7.16.4 7.16.3 ≤ 7.16.3 7.16.2 ≤ 7.16.2 7.16.1 ≤ 7.16.1 7.16.0 ≤ 7.16.0 7.15.5 ≤ 7.15.5 7.15.4 ≤ 7.15.4 7.15.3 ≤ 7.15.3 7.15.2 ≤ 7.15.2 7.15.1 ≤ 7.15.1 7.15.0 ≤ 7.15.0 7.14.1 ≤ 7.14.1 7.14.0 ≤ 7.14.0 7.13.2 ≤ 7.13.2 7.13.1 ≤ 7.13.1 7.13.0 ≤ 7.13.0 7.12.3 ≤ 7.12.3 7.12.2 ≤ 7.12.2 7.12.1 ≤ 7.12.1 7.12.0 ≤ 7.12.0 7.11.2 ≤ 7.11.2 7.11.1 ≤ 7.11.1 7.11.0 ≤ 7.11.0 7.10.8 ≤ 7.10.8 7.10.7 ≤ 7.10.7 7.10.6 ≤ 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