curl: Insufficiently Protected Credentials
CVE-2026-8926 is a critical-severity insufficiently protected credentials vulnerability in curl, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 8.14.2, 8.16.1, 8.20.1 as the first without the flaw, so updating curl to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.44% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update curl to 8.14.2 or 8.16.1 or 8.20.1 or 4ae1d7cc2643e4773a136395f12bc02fc6867854, whichever matches your release line, or a later version.
- Read the advisory on curl.se for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Curl | curl | 8.11.1 up to, but not including, 8.14.2; 8.15.0 up to, but not including, 8.16.1; 8.17.0 up to, but not including, 8.20.1; e9b9bbac22c26cf67316fa8e6c6b9e831af31949 up to, but not including, 4ae1d7cc2643e4773a136395f12bc02fc6867854; 8.20.0; 8.19.0; 8.18.0; 8.17.0; and 8 more ranges | 8.14.2, 8.16.1, 8.20.1, 4ae1d7cc2643e4773a136395f12bc02fc6867854 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CISA (ADP).
Official description
When asking curl to use a `.netrc` file to find credentials and at the same time specifying a URL with a username (without a password), like `https://[email protected]/`, curl could wrongly get and use the password for *another* user set in the `.netrc` file for that host if such a one exists and there is no match for the specified user.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Insufficiently Protected Credentials
The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.
How developers prevent this class of flaw
- Use an appropriate security mechanism to protect the credentials.
- Make appropriate use of cryptography to protect the credentials.
- Use industry standards to protect the credentials (e.g. LDAP, keystore, etc.).
More Insufficiently Protected Credentials vulnerabilities (CWE-522)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- hackerone.com/reports/3735184Exploit, Issue Tracking, Third Party Advisory
Other vulnerabilities in curl
- 7.5 High severity
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 9.1 Critical severity
Recent Insufficiently Protected Credentials vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 7.1 High severity
- 7.7 High severity
- 9.1 Critical severity
- 7.5 High severity
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