CVE-2026-27193

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 72% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
5.3
EG Score
5.3(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
29%
KEV
Not listed

Published

February 21, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Aug 7, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

Internal headers exposed via unencrypted session cookie · Advisory · feathersjs/feathers · GitHub

https://github.com/feathersjs/feathers/security/advisories/GHSA-9m9c-vpv5-9g85
github_release Patch Available

v5.0.40

Patch available: feathersjs/feathers v5.0.40

https://github.com/feathersjs/feathers/releases/tag/v5.0.40
github_commit Patch Available

commit ee19a0ae9bc2 (feathersjs/feathers)

Patch available: feathersjs/feathers v5.0.40 (contains commit ee19a0ae9bc2)

https://github.com/feathersjs/feathers/commit/ee19a0ae9bc2ebf23b1fe598a1f7361981b65401

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
@feathersjs/authentication-oauth—5.0.40—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 26× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 20:06 UTCOSV refresh
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 19:27 UTCEPSS rescore
  4. 2026-09-17 19:30 UTCEPSS rescore
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-12 15:01 UTCEPSS rescore
  9. 2026-09-11 14:52 UTCEPSS rescore
  10. 2026-09-10 09:34 UTCEPSS rescore
  11. 2026-09-08 22:00 UTCEPSS rescore
  12. 2026-09-07 16:01 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-04 05:06 UTCEPSS rescore
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-08-30 23:03 UTCOSV refresh
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:48 UTCEPSS rescore
Show 32 more
  1. 2026-08-21 23:49 UTCEPSS rescore
  2. 2026-08-20 22:55 UTCEPSS rescore
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-18 13:48 UTCEPSS rescore
  5. 2026-08-17 13:47 UTCEPSS rescore
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-16 02:14 UTCEPSS rescore
  8. 2026-08-15 01:30 UTCEPSS rescore
  9. 2026-08-14 09:18 UTCEG score recompute
  10. 2026-08-13 22:00 UTCEPSS rescore
  11. 2026-08-13 01:22 UTCEG score recompute
  12. 2026-08-12 13:50 UTCEPSS rescore
  13. 2026-08-11 13:42 UTCEPSS rescore
  14. 2026-08-11 07:24 UTCEG score recompute
  15. 2026-08-11 00:00 UTCEPSS rescore
  16. 2026-08-10 09:16 UTCEG score recompute
  17. 2026-08-09 13:46 UTCEPSS rescore
  18. 2026-08-09 08:56 UTCEG score recompute
  19. 2026-08-08 16:37 UTCEPSS rescore
  20. 2026-08-07 21:04 UTCEG score recompute
  21. 2026-08-06 13:46 UTCEPSS rescore
  22. 2026-08-06 03:16 UTCEG score recompute
  23. 2026-08-05 19:17 UTCEPSS rescore
  24. 2026-08-04 15:10 UTCEPSS rescore
  25. 2026-08-03 10:36 UTCEPSS rescore
  26. 2026-08-02 19:52 UTCEG score recompute
  27. 2026-08-02 02:26 UTCEPSS rescore
  28. 2026-08-01 04:16 UTCEPSS rescore
  29. 2026-07-30 16:27 UTCEPSS rescore
  30. 2026-07-30 01:30 UTCEPSS rescore
  31. 2026-07-28 15:36 UTCEPSS rescore
  32. 2026-07-27 14:10 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-27193?
CVE-2026-27193 is a medium vulnerability published on February 21, 2026. 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…
When was CVE-2026-27193 disclosed?
CVE-2026-27193 was first published in the National Vulnerability Database on February 21, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27193 actively exploited?
CVE-2026-27193 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 70.9% of all scored CVEs.
What is the CVSS score of CVE-2026-27193?
CVE-2026-27193 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-27193?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27193, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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