CVE-2026-9079: curl Credential Exposure

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.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0106

Probability of exploitation

0.61%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-522 CWE-522

Affected Products

Vendor	Product	Versions
haxx	curl	8.8.0 — 8.21.0

References

Advisories & Patches

https://curl.se/docs/CVE-2026-9079.html https://curl.se/docs/CVE-2026-9079.json

Exploits

https://hackerone.com/reports/3750295 https://hackerone.com/reports/3750295

Frequently Asked Questions

What is CVE-2026-9079? +

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-9079? +

CVE-2026-9079 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0106, placing it in the 1th percentile for exploitation probability.

What products are affected by CVE-2026-9079? +

CVE-2026-9079 affects products from haxx, specifically: curl. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-9079? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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