CVE-2026-27193
published 2026-02-21CVE-2026-27193: 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…
PriorityP432medium5.3CVSS 3.1
AVNACHPRLUINSUCHINAN
EPSS
0.35%
27.3th percentile
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.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| feathersjs | authentication-oauth | >= 0 < 5.0.40 | 5.0.40 |
| feathersjs | feathers | < 5.0.40 | 5.0.40 |
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
nvdv4.08.2HIGHCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
OSV
Feathers exposes internal headers via unencrypted session cookie
osv·2026-02-19
CVE-2026-27193 [HIGH] Feathers exposes internal headers via unencrypted session cookie
Feathers exposes internal headers via unencrypted session cookie
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:
```javascript
// https://github.com/feathersjs/feathers/blob/dove/packages/authentication-oauth/src/service.ts#L173
session.headers = headers;
```
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
GHSA
Feathers exposes internal headers via unencrypted session cookie
ghsa·2026-02-19
CVE-2026-27193 [HIGH] CWE-200 Feathers exposes internal headers via unencrypted session cookie
Feathers exposes internal headers via unencrypted session cookie
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:
```javascript
// https://github.com/feathersjs/feathers/blob/dove/packages/authentication-oauth/src/service.ts#L173
session.headers = headers;
```
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
No detection rules found.
No public exploits indexed.
2026-02-21
Published