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High 8.2Published Feb 20, 2026

CVE-2026-27193Feathers exposes internal headers via unencrypted session cookie

Updated under an hour ago ()

Does this affect you?

It affects feathersjs feathers. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, all HTTP request headers are stored in the session cookie, which is signed but not encrypted, exposing internal proxy/gateway headers to clients. The OAuth service stores the complete headers object in the session, then the session is persisted using cookie-session, which base64-encodes the data. While the cookie is signed to prevent tampering, the contents are readable by anyone by simply decoding the base64 value. Under specific deployment configurations (e.g., behind reverse proxies or API gateways), this can lead to exposure of sensitive internal infrastructure details such as API keys, service tokens, and internal IP addresses. This issue has been fixed in version 5.0.40.

CVSS
8.2 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-200
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitHub_M
NVD analysis
Analyzed
Record last updated
Feb 25, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
feathersjs feathers
feathersjs:feathers (from the name)
before 5.0.40
CNA record
feathersjs feathers
feathersjs:feathers
before 5.0.40
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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