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Fencer Vulns
critical 9.1

CVE-2026-86413 json

Negotiate credentials sent to redirected origin

published 2026-10-20 19 d ago modified 2026-10-30 10 d ago also EUVD-2026-105279

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

When using an *ambient user* in a first transfer doing Negotiate authentication and asked to follow redirects, curl could pass on its credential details to an unrelated second origin when asked to redirect there.

Patch / fix

  • haxx curl 8.23.0
  • curl hummingbird 1 8.23.0-0.1.hum1
  • libcurl hummingbird 1 8.23.0-0.1.hum1
  • libcurl-minimal hummingbird 1 8.23.0-0.1.hum1

red hat advisories RHSA-2026:82895

  • curl SLE Module for Basesystem 15 SP7 8.22.0-150700.7.33.1
  • curl SLES for SAP 15 SP6, SLES 15 SP6-LTSS 8.22.0-150600.4.58.1

suse advisories SUSE-SU-2026:5069-1SUSE-SU-2026:5068-1

  • curl openSUSE Tumbleweed 8.23.0-1.1

opensuse advisories openSUSE-SU-2026:12150-1

  • curl Alpine 3.24, Alpine 3.23 8.23.0-r0

alpine advisories ALPINE-CVE-2026-86413

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-86413 updated cvss 5.3

curl: curl: Negotiate credentials sent to redirected origin

  • Red Hat Hardened Images curl 8.23.0-0.1.hum1, libcurl 8.23.0-0.1.hum1, libcurl-minimal 8.23.0-0.1.hum1
    fixed: vendor fix RHSA-2026:82895
  • Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl Red Hat Enterprise Linux 8 curl, libcurl, libcurl-minimal Red Hat Enterprise Linux 9 curl, rust, cargo, clippy, libcurl, rustfmt, +13 more Red Hat Enterprise Linux 10 curl, igvm, rust, snphost, trustee, s390utils Red Hat Hardened Images rust
    +2 more products
    Red Hat JBoss Core Services jbcs-httpd24-curl, jbcs-httpd24-libcurl Red Hat Satellite 6 foreman, foreman-cli, foreman-ec2, foreman-gce, puppet-agent, foreman-ovirt, +11 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
10 d ago

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/3993549 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

  • curl curl

Classification

Weakness
  • CWE-201 Insertion of Sensitive Information Into Sent Data

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.