What is CVE-2026-22779?

CVE-2026-22779 is a medium-severity security vulnerability in blacksheep (pip), affecting versions < 2.4.6. It is fixed in 2.4.6.

Which versions of blacksheep are affected by CVE-2026-22779?

blacksheep (pip) versions < 2.4.6 is affected.

Is there a fix for CVE-2026-22779?

Yes. CVE-2026-22779 is fixed in 2.4.6. Upgrade to this version or later.

Is CVE-2026-22779 exploitable, and should I be worried?

Whether CVE-2026-22779 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-22779 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-22779?

Upgrade blacksheep to 2.4.6 or later.

CVE-2026-22779 in blacksheep

Q: Which versions of blacksheep are affected by CVE-2026-22779?

blacksheep (pip) versions < 2.4.6 is affected.

Q: Is there a fix for CVE-2026-22779?

Yes. CVE-2026-22779 is fixed in 2.4.6. Upgrade to this version or later.

Q: Is CVE-2026-22779 exploitable, and should I be worried?

Whether CVE-2026-22779 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-22779 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-22779?

Upgrade blacksheep to 2.4.6 or later.

Summary

BlackSheep's ClientSession is vulnerable to CRLF injection

Workarounds

If users handle headers from untrusted parties, they might reject values for header names and values that contain carriage returns.

References

https://owasp.org/www-community/vulnerabilities/CRLF_Injection

Impact

The HTTP Client implementation in BlackSheep is vulnerable to CRLF injection. Missing headers validation makes it possible for an attacker to modify the HTTP requests (e.g. insert a new header) or even create a new HTTP request.
Exploitation requires developers to pass unsanitized user input directly into headers.
The server part is not affected because BlackSheep delegates to an underlying ASGI server handling of response headers.

Attack vector: Applications using user input in HTTP client requests (method, URL, headers).

Affected versions

blacksheep (< 2.4.6)

Security releases

blacksheep → 2.4.6 (pip)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Users who use the HTTP Client in BlackSheep should upgrade to 2.4.6.

Frequently Asked Questions

What is CVE-2026-22779? CVE-2026-22779 is a medium-severity security vulnerability in blacksheep (pip), affecting versions < 2.4.6. It is fixed in 2.4.6.
Which versions of blacksheep are affected by CVE-2026-22779? blacksheep (pip) versions < 2.4.6 is affected.
Is there a fix for CVE-2026-22779? Yes. CVE-2026-22779 is fixed in 2.4.6. Upgrade to this version or later.
Is CVE-2026-22779 exploitable, and should I be worried? Whether CVE-2026-22779 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-22779 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-22779? Upgrade blacksheep to 2.4.6 or later.