CVE-2026-43969
3.2 · LOWOverview
CVE-2026-43969 is a low-severity vulnerability affecting ninenines cowlib. It was published on May 11, 2026 and has a CVSS 3.1 base score of 3.2 (LOW).
This vulnerability has a CVSS 3.1 base score of 3.2, rated LOW. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
Technical Description
Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in ninenines cowlib allows HTTP request splitting and cookie smuggling via unvalidated cookie name and value fields.
cow_cookie:cookie/1 in cowlib builds a client-side Cookie: request header from a list of name-value pairs without validating either field. An attacker who controls the cookie names or values passed to this function can inject ;, ,, CR, LF, or TAB characters into the serialized header. This enables two classes of attack: cookie smuggling within a single header (e.g. injecting ; admin=1 to introduce a phantom cookie that the receiving server treats as authentic) and HTTP request header splitting (injecting CRLF to append arbitrary headers or smuggle a complete second request against a shared upstream proxy). The decoder side (parse_cookie_name/1, parse_cookie_value/1) and setcookie/3 already validate and reject these characters; the encoder alone is missing the check.
This issue affects cowlib: fr
Remediation
Check the references section for vendor advisories and patches from ninenines. Update cowlib to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| ninenines | cowlib | 2.9.0 | Affected |
Frequently Asked Questions
What is CVE-2026-43969?
CVE-2026-43969 is a low-severity vulnerability affecting ninenines cowlib. It was published on May 11, 2026 and has a CVSS 3.1 base score of 3.2 (LOW).
How severe is CVE-2026-43969?
This vulnerability has a CVSS 3.1 base score of 3.2, rated LOW. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-43969?
Check the references section for vendor advisories and patches from ninenines. Update cowlib to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-43969?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-43969 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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