CVE-2026-9079 | stale proxy password leak

Exp

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.

Published: 2026-07-03 Last update: 2026-07-07 Assigner: 2499f714-1537-4658-8207-48ae4bb9eae9 Source: 2499f714-1537-4658-8207-48ae4bb9eae9
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-9079 is rated High Exploit Risk (75.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.06%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-9079

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-9079

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-09 0.75% 1.06% +0.31%
2 2026-07-07 0.25% 0.75% +0.50%
3 2026-07-04 — 0.25% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-9079

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-9079

GitHub Security Advisory for CVE-2026-9079

GHSA-f4cv-xm48-3694 · Severity: critical — libcurl had a flaw that when instructed to clear proxy authentication credentials which made it...

OS Trackers for CVE-2026-9079

vendor priority summary link
debian unimportant CVE-2026-9079 unimportant priority: Debian including 1 source packages (curl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2026-9079
suse high CVE-2026-9079 severity important: SUSE including 24 source package names (curl, curl-8.14.1-150400.5.86.1, …), 98 product×package rows across 30 product lines (Container suse/sles/16.0/toolbox, SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS, … (30 product lines)): First Fixed 82, Known Not Affected 14, Fixed 2. https://www.suse.com/security/cve/CVE-2026-9079/
ubuntu medium CVE-2026-9079 medium priority: Ubuntu including 1 source packages (curl), 9 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): not-affected 6, released 2, pending 1. https://ubuntu.com/security/CVE-2026-9079

Affected software / configurations for CVE-2026-9079

Vendor Product Version Raw CPE
haxx curl >= 8.8.0, < 8.21.0 cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

References for CVE-2026-9079

URL Tags
https://curl.se/docs/CVE-2026-9079.html Patch Vendor Advisory
https://curl.se/docs/CVE-2026-9079.json Vendor Advisory
https://hackerone.com/reports/3750295 Exploit Issue Tracking Third Party Advisory
cvelogic Threat Intelligence