CVE-2026-11856

Aliases:DEBIAN-CVE-2026-11856UBUNTU-CVE-2026-11856USN-8651-1ALPINE-CVE-2026-11856CGA-283w-2j5q-8mc9CGA-4hvp-ggcf-v62vCGA-6hmx-9x2r-c7qwCGA-6q8p-5phh-gp9pCGA-85f5-9hgx-9qvrCGA-c5p2-6fjw-m9hcCGA-cjh2-7rjc-f3hxCGA-cpv8-328h-jmqfCGA-ggmh-36wf-wxh8CGA-h322-v395-hq4hCGA-hw2c-8257-9jwjCGA-j455-fpqm-53hgCGA-mg5c-8xgv-3pg3CGA-mgjq-524h-jj64CGA-pghg-fpqq-g26mCGA-r9jj-cmqj-9vr2CGA-w3v5-wqmw-6jfxCGA-ww9q-fqm2-9hv2CGA-x2mw-ph27-fppgCGA-xvf6-74x6-vgcwCGA-x635-4h7x-365g
Advisory lineage Upstream: 1 Downstream: 6
Modified
Published: 03 Jul 2026, 06:13
Last modified:15 Sept 2026, 06:02

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (cve.org)
EPSS Score
0.69% LOW
1% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

03 Jul 2026, 06:13
Published
Vulnerability first disclosed
15 Sept 2026, 06:02
Last Modified
Vulnerability information updated

Description

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`.

CVSS Metrics

  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.69%• Percentile: 51%

Techniques & Countermeasures

  • CWE-294•Authentication Bypass by Capture-replay

    A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

Affected Systems

  • alpine•curl

    ≥ 7.10.6, < 8.22.0-r0 | ≥ 7.10.6, < 8.21.0-r0

  • chainguard•eco-python-curl

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-bin

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-dev

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-doc

    < 8.21.0-r0

  • chainguard•eco-python-curl-minimal-static

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2-bin

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2-dev

    < 8.21.0-r0

  • chainguard•eco-python-curl-nghttp2-static

    < 8.21.0-r0

  • chainguard•libcurl4

    all

  • wolfi•libcurl4

    all

  • 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 | ≥ 7.10.6, < 8.14.2 | ≥ 8.15.0, < 8.16.1 | ≥ 8.17.0, < 8.20.1 | ≥ 334d78cd18a7310144383929bdcef34ffbf6159b, < 5c6b4880357ab3e72967c1c45cae0f96ffabc535 | 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

  • debian•curl

    all | all | all | < 8.21.0~rc3-1

  • ubuntu•curl

    all | all | all | all | < 7.35.0-1ubuntu2.20+esm22 | < 7.47.0-1ubuntu2.19+esm18 | < 7.58.0-2ubuntu3.24+esm11 | < 7.68.0-1ubuntu2.25+esm6 | < 7.81.0-1ubuntu1.26 | < 8.5.0-2ubuntu10.12 | < 8.18.0-1ubuntu2.4 | all

  • haxx•curl

    ≥ 7.10.6, < 8.21.0

References (11)