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Fencer Vulns
medium 6.5

CVE-2026-8458 json

wrong reuse for different services

published 2026-07-03 4 mo ago modified 2026-09-15 55 d ago also EUVD-2026-41504 , GHSA-88c6-6jfq-mm4q , JLSEC-2026-1212

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services".

libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.

When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.

Patch / fix

  • julia CURL_jll 8.20.0+0
  • julia LibCURL_jll 8.20.0+0
  • curl curl 8.14.2, 8.16.1, 8.20.1
  • curl Debian 14 8.21.0~rc2-1

debian advisories DEBIAN-CVE-2026-8458

  • curl Ubuntu 22.04 LTS 7.81.0-1ubuntu1.25
  • curl Ubuntu 24.04 LTS 8.5.0-2ubuntu10.10
  • curl Ubuntu 25.10 8.14.1-2ubuntu1.4
  • curl Ubuntu 26.04 LTS 8.18.0-1ubuntu2.2
  • curl Ubuntu Pro 18.04 LTS 7.58.0-2ubuntu3.24+esm9
  • curl Ubuntu Pro 20.04 LTS 7.68.0-1ubuntu2.25+esm4

ubuntu advisories UBUNTU-CVE-2026-8458

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • curl RHEL 9 7.76.1-40.el9_8.7
  • libcurl RHEL 9 7.76.1-40.el9_8.7
  • curl-minimal RHEL 9 7.76.1-40.el9_8.7
  • libcurl-minimal RHEL 9 7.76.1-40.el9_8.7
  • curl RHEL 10.2 8.12.1-4.el10_2.6
  • libcurl RHEL 10.2 8.12.1-4.el10_2.6
  • libcurl-minimal RHEL 10.2 8.12.1-4.el10_2.6
  • curl hummingbird 1 8.21.0-0.1.hum1

red hat advisories RHSA-2026:72506RHSA-2026:69126RHSA-2026:69125RHSA-2026:29017RHSA-2026:34975

  • curl Linux Micro 6.1 8.14.1-slfo.1.1_8.1
  • curl SLES 15 SP5-LTSS, SLES 15 SP4-LTSS, SLE Micro 5.5 +8 more 8.14.1-150400.5.86.1
  • curl Linux Micro 6.0 8.14.1-7.1
  • curl SLE Module for Basesystem 15 SP7 8.14.1-150700.7.20.1
  • curl SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 8.14.1-160000.8.1
  • curl-mini SLES for SAP applications 16.0, SLES 16.0 8.14.1-160000.8.1
  • curl SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 8.0.1-11.134.1
  • curl SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 8.0.1-11.126.1

suse advisories SUSE-SU-2026:5071-1SUSE-SU-2026:3814-1SUSE-SU-2026:22889-1SUSE-SU-2026:3043-1SUSE-SU-2026:22709-1SUSE-SU-2026:2926-1

  • curl openSUSE Tumbleweed 8.21.0-1.1
  • curl openSUSE Leap 16.0 8.14.1-160000.8.1

opensuse advisories openSUSE-SU-2026:11230-1openSUSE-SU-2026:21272-1

  • curl AlmaLinux 8 7.61.1-34.el8_10.18
  • libcurl AlmaLinux 8 7.61.1-34.el8_10.18
  • libcurl-minimal AlmaLinux 8 7.61.1-34.el8_10.18
  • curl AlmaLinux 10 8.12.1-4.el10_2.6
  • libcurl AlmaLinux 10 8.12.1-4.el10_2.6
  • libcurl-minimal AlmaLinux 10 8.12.1-4.el10_2.6
  • curl AlmaLinux 9 7.76.1-40.el9_8.7
  • libcurl AlmaLinux 9 7.76.1-40.el9_8.7

almalinux advisories ALSA-2026:92368ALSA-2026:69125ALSA-2026:69126

  • curl Rocky Linux 8 7.61.1-34.el8_10.18
  • curl Rocky Linux 9 7.76.1-40.el9_8.7
  • curl Rocky Linux 10 8.12.1-4.el10_2.6

rocky linux advisories RLSA-2026:92368RLSA-2026:69126RLSA-2026:69125

  • curl Alpine 3.23 8.22.0-r0
  • curl Alpine 3.24 8.21.0-r0

alpine advisories ALPINE-CVE-2026-8458

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

  • curl Azure Linux 3.0 8.11.1-10
  • cmake Azure Linux 3.0 3.30.3-15

azure linux advisories AZL-91809AZL-91824

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2026-8458 updated cvss 8.1

curl: libcurl: Unauthorized connection reuse due to a logical error

  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    affected: workaround, no fix available
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/cert-manager-operator-rhel9 1790272426, cert-manager/cert-manager-operator-rhel9 1790589855, cert-manager/jetstack-cert-manager-rhel9 1790223279, cert-manager/jetstack-cert-manager-rhel9 1790589912, cert-manager/cert-manager-istio-csr-rhel9 1790223719, cert-manager/cert-manager-istio-csr-rhel9 1790589914, +1 more
    fixed: vendor fix RHSA-2026:72475
  • Red Hat Cost Management On-Premise 1 costmanagement/costmanagement-ui-rhel10 1791460851
    fixed: vendor fix RHSA-2026:79357
  • Red Hat Enterprise Linux AppStream (v. 9) libcurl-devel 7.76.1-40.el9_8.7, curl-debuginfo 7.76.1-40.el9_8.7, curl-debugsource 7.76.1-40.el9_8.7, libcurl-debuginfo 7.76.1-40.el9_8.7, curl-minimal-debuginfo 7.76.1-40.el9_8.7, libcurl-minimal-debuginfo 7.76.1-40.el9_8.7
    fixed: vendor fix RHSA-2026:69126
  • Red Hat Enterprise Linux AppStream (v. 10) libcurl-devel 8.12.1-4.el10_2.6, curl-debuginfo 8.12.1-4.el10_2.6, curl-debugsource 8.12.1-4.el10_2.6, libcurl-debuginfo 8.12.1-4.el10_2.6, libcurl-minimal-debuginfo 8.12.1-4.el10_2.6
    fixed: vendor fix RHSA-2026:69125
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) libcurl-devel 8.12.1-1.el10_0.10, curl-debuginfo 8.12.1-1.el10_0.10, curl-debugsource 8.12.1-1.el10_0.10, libcurl-debuginfo 8.12.1-1.el10_0.10, libcurl-minimal-debuginfo 8.12.1-1.el10_0.10
    fixed: vendor fix RHSA-2026:72506
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) libcurl-devel 7.76.1-31.el9_6.4, curl-debuginfo 7.76.1-31.el9_6.4, curl-debugsource 7.76.1-31.el9_6.4, libcurl-debuginfo 7.76.1-31.el9_6.4, curl-minimal-debuginfo 7.76.1-31.el9_6.4, libcurl-minimal-debuginfo 7.76.1-31.el9_6.4
    fixed: vendor fix RHSA-2026:93454
  • Red Hat Enterprise Linux BaseOS (v. 8) curl 7.61.1-34.el8_10.18, libcurl 7.61.1-34.el8_10.18, libcurl-minimal 7.61.1-34.el8_10.18
    fixed: vendor fix RHSA-2026:92368
show 10 more
  • Red Hat Enterprise Linux BaseOS (v. 9) curl 7.76.1-40.el9_8.7, libcurl 7.76.1-40.el9_8.7, curl-minimal 7.76.1-40.el9_8.7, libcurl-minimal 7.76.1-40.el9_8.7
    fixed: vendor fix RHSA-2026:69126
  • Red Hat Enterprise Linux BaseOS (v. 10) curl 8.12.1-4.el10_2.6, libcurl 8.12.1-4.el10_2.6, libcurl-minimal 8.12.1-4.el10_2.6
    fixed: vendor fix RHSA-2026:69125
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) curl 8.12.1-1.el10_0.10, libcurl 8.12.1-1.el10_0.10, libcurl-minimal 8.12.1-1.el10_0.10
    fixed: vendor fix RHSA-2026:72506
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) curl 7.76.1-31.el9_6.4, libcurl 7.76.1-31.el9_6.4, curl-minimal 7.76.1-31.el9_6.4, libcurl-minimal 7.76.1-31.el9_6.4
    fixed: vendor fix RHSA-2026:93454
  • Red Hat Hardened Images rust 1.96.1-1.hum1, cargo 1.96.1-1.hum1, clippy 1.96.1-1.hum1, curl 8.21.0-0.1.hum1, rustfmt 1.96.1-1.hum1, rust-gdb 1.96.1-1.hum1, +14 more
    fixed: vendor fix RHSA-2026:34975
  • Red Hat JBoss Core Services 2.4.62.SP5
    fixed: vendor fix RHSA-2026:56869
  • Red Hat OpenShift Container Platform 4.22 rhcos 4.22.9.8.202611032353
    fixed: vendor fix RHSA-2026:95346
  • Red Hat OpenShift Dev Spaces 3.30 devspaces/code-rhel9 1790619703
    fixed: vendor fix RHSA-2026:73516
  • Red Hat Update Infrastructure 5 rhui5/cds-rhel9 1790241954, rhui5/rhua-rhel9 1790242004, rhui5/haproxy-rhel9 1790241900, rhui5/installer-rhel9 1790241922, rhui5/cds-kubernetes-rhel9 1790241897
    fixed: vendor fix RHSA-2026:71603
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/jetstack-cert-manager-acmesolver-rhel9 1790223630 Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl Red Hat OpenShift AI (RHOAI) rhoai/odh-llama-stack-k8s-operator-rhel9 Red Hat OpenShift Dev Spaces 3.30 devspaces/udi-rhel9 1790369528, devspaces/server-rhel9 1790625554, devspaces/openvsx-rhel9 1790616590, devspaces/traefik-rhel9 1790615456, devspaces/udi-base-rhel9 1790366977, devspaces/code-sshd-rhel9 1790618567, +9 more Red Hat Trusted Profile Analyzer rhtpa/rhtpa-trustification-service-rhel9
    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
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/3721183 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
julia CURL_jll
<8.20.0+0
8.20.0+0
julia LibCURL_jll
<8.20.0+0
8.20.0+0

Affected products

  • curl curl

Classification

Weakness
  • CWE-488 Exposure of Data Element to Wrong Session

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.