password leak with netrc and user in URL (CVE-2026-8926)
Published Last modified Sources: Red Hat, Ubuntu, BSI, SUSE, Msrc Update Guide, CVE.org, OSV
What is affected, what to do
A flaw was found in curl. When curl is configured to use a .netrc file for credentials and a URL is provided with a username but no password, curl may incorrectly retrieve and use the password for a different user from the .netrc file for the same host.
Update Curl to version 8.14.2, Curl to version 8.16.1, Curl to version 8.20.1.
- Affected
- Curl
lt 8.11.1..8.14.2 - Curl
lt 8.15.0..8.16.1 - Curl
lt 8.17.0..8.20.1 - Curl
eq 8.20.0..8.20.0 - Curl
eq 8.19.0..8.19.0 - Curl
eq 8.18.0..8.18.0 - Curl
eq 8.17.0..8.17.0 - Curl
eq 8.16.0..8.16.0 - Curl
eq 8.15.0..8.15.0 - Curl
eq 8.14.1..8.14.1 - Curl
eq 8.14.0..8.14.0 - Curl
eq 8.13.0..8.13.0 - Curl
eq 8.12.1..8.12.1 - Curl
eq 8.12.0..8.12.0 - Curl
eq 8.11.1..8.11.1
- Curl
- Fixed in
- Curl
8.14.2 - Curl
8.16.1 - Curl
8.20.1
- Curl
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Metrics
5.9
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
5.9
CVSS v3
Severity Medium on the scale from 0 to 10.
Source: Red Hat, Ubuntu, BSI, SUSE, Msrc Update Guide, CVE.org, OSV
0.4 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 38.3
Show all metrics
- Severity
- Medium
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 61.35 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 5.9 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 5.9
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.4 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 38.3
- High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-522
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
A flaw was found in curl. When curl is configured to use a .netrc file for credentials and a URL is provided with a username but no password, curl may incorrectly retrieve and use the password for a different user from the .netrc file for the same host. This could lead to unauthorized information disclosure, as curl might connect using unintended credentials.
Source: redhat_csaf, Ubuntu Security Notices, BSI WID Portal, BSI CSAF, suse_csaf, Microsoft Security Update Guide, cvelistv5, NVD (NIST), CVE.org (MITRE), OSV (Open Source Vulnerabilities)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| curl | curl |
|
|
| haxx | curl |
|
|
| Open Source | cURL |
|
|
Vendors and products
Affected operating systems
| Linux | ubuntu | curl | trusty |
Weakness classes (CWE)
CWE-522Insufficiently Protected Credentials
Class
The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.
Entry at MITRE CWE-522
References & sources
- curl.sejson
- curl.sewww
- hackerone.comissue
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedcurl
Weakness type: CWE-522
Description added or changed
Show 12 original changes
Individual changes of this event as published by NVD Type Action Before After Description changed 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://user@example.com/`, 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.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://user@example.com/`, 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.Weakness type (CWE) added —CWE-522Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/8xxx/CVE-2026-8926.json">CVE-2026-8926</a>Reference added —https://curl.se/docs/CVE-2026-8926.htmlReference added —https://curl.se/docs/CVE-2026-8926.jsonReference added —https://hackerone.com/reports/3735184Reference removed https://curl.se/docs/CVE-2026-8926.html—Reference removed https://curl.se/docs/CVE-2026-8926.json—Reference removed https://hackerone.com/reports/3735184—Reference type removed https://curl.se/docs/CVE-2026-8926.html Types: Patch, Vendor Advisory—Reference type removed https://curl.se/docs/CVE-2026-8926.json Types: Vendor Advisory—Reference type removed https://hackerone.com/reports/3735184 Types: Exploit, Issue Tracking, Third Party Advisory—Source identifier: 2499f714-1537-4658-8207-48ae4bb9eae9
Record modifiedCISA ADP
New references:Show 3 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —https://hackerone.com/reports/3735184Reference removed https://hackerone.com/reports/3735184—Reference type removed https://hackerone.com/reports/3735184 Types: Exploit, Issue Tracking, Third Party Advisory—Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Initial analysis by NVDNVD
Newly listed as affected:- Google Haxx Curl (8.11.1 – before 8.21.0)
Weakness type: CWE-522
Show 6 original changes
Individual changes of this event as published by NVD Type Action Before After Weakness type (CWE) added —CWE-522Product configuration added —OR *cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* versions from (including) 8.11.1 up to (excluding) 8.21.0Reference type added —curl: https://curl.se/docs/CVE-2026-8926.html Types: Patch, Vendor AdvisoryReference type added —curl: https://curl.se/docs/CVE-2026-8926.json Types: Vendor AdvisoryReference type added —curl: https://hackerone.com/reports/3735184 Types: Exploit, Issue Tracking, Third Party AdvisoryReference type added —CISA-ADP: https://hackerone.com/reports/3735184 Types: Exploit, Issue Tracking, Third Party AdvisorySource identifier: nvd@nist.gov
Receivedcurl
Description added or changed
Show 5 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —curlDescription added —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://user@example.com/`, 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.Reference added —https://curl.se/docs/CVE-2026-8926.htmlReference added —https://curl.se/docs/CVE-2026-8926.jsonReference added —https://hackerone.com/reports/3735184Source identifier: 2499f714-1537-4658-8207-48ae4bb9eae9
Linked advisories
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-8926"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-8926.svg?lang=en" alt="CVE-2026-8926 – NEOSEC Intel" height="20"></a>