CVE-2026-9079 — curl
CRITICALCVE-2026-9079 is a critical-severity (CVSS 9.8) CWE-522 vulnerability. A fix is available — see the affected versions and patch details below.
stale proxy password leak
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-9079.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-9079 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
libcurl had a flaw that when instructed to clear proxy authentication credentials which made it not do so, leaving the old credentials around to get used for subsequent transfers that should not know nor use them.
Affected Products
curlhaxxDetection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-9079, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Important: A flaw in libcurl's proxy authentication credential management can lead to information disclosure. There are no integrity or availability risks posed by this flaw.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2026-9079 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | curl-0:8.12.1-4.el10_2.6 | RHSA-2026:69125 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | curl-0:8.12.1-1.el10_0.10 | RHSA-2026:72506 |
| Red Hat JBoss Core Services 2.4.62.SP5 | libcurl-1.dll | RHSA-2026:56869 |
| Red Hat Cost Management On-Premise 1 | costmanagement/costmanagement-ui-rhel10:1791460851 | RHSA-2026:79357 |
| Red Hat Hardened Images | curl-main-8.21.0-0.1.hum1 | RHSA-2026:29017 |
| Red Hat Hardened Images | rust-main-1.96.1-1.hum1 | RHSA-2026:34975 |
Frequently Asked Questions
Is CVE-2026-9079 in your dependencies?
Find it across , including transitive dependencies.