How severe is CVE-2026-22779?

No CVSS score has been assigned to CVE-2026-22779 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-22779?

CVE-2026-22779 affects the following packages: blacksheep (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-22779?

Update blacksheep to 2.4.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-22779 is resolved across your whole dependency graph.

How do I detect CVE-2026-22779 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for blacksheep, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-22779 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-22779 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-22779 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-22779?

CVE-2026-22779 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 31th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-22779?

CVE-2026-22779 is classified as CWE-113 (CWE-113). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-22779 published, and has it been updated?

CVE-2026-22779 was published on January 14, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2026-22779 — blacksheep

Fix: Neoteroi/BlackSheep@bd4ecb9

CVE-2026-22779 is a CWE-113 vulnerability in blacksheep. A fix is available for blacksheep — see the affected versions and patch details below.

BlackSheep ClientSession is vulnerable to CRLF injection

Also known asGHSA-6pw3-h7xf-x4gpPYSEC-2026-1222

Published

Jan 14, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-22779.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐍blacksheep

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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).

Patches

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

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

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`blacksheep`	all versions	2.4.6`pip install --upgrade 'blacksheep==2.4.6'`

Affected Products

1 product · 1 configurations

Application

blacksheepneoteroi

< 2.4.6

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for blacksheep, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update blacksheep to 2.4.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-22779 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### 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). ### Patches Users who use the HTTP Client in BlackShee

O3 Security · Impact-Aware SCA

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