CVE-2023-48223

MEDIUMNVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under NVD CVSS v3. EPSS exploit probability: 0.7%, top 27% 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
5.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 5.9Exploit: NoneExposed: 0

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

fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to version 3.3.2, the fast-jwt library does not properly prevent JWT algorithm confusion for all public key types. The 'publicKeyPemMatcher' in 'fast-jwt/src/crypto.js' does not properly match all common PEM formats for public keys. To exploit this vulnerability, an attacker needs to craft a malicious JWT token containing the HS256 algorithm, signed with the public RSA key of the victim application. This attack will only work if the victim application utilizes a public key containing the BEGIN RSA PUBLIC KEY header. Applications using the RS256 algorithm, a public key with a BEGIN RSA PUBLIC KEY header, and calling the verify function without explicitly providing an algorithm, are vulnerable to this algorithm confusion attack which allows attackers to sign arbitrary payloads which will be accepted by the verifier. Version 3.3.2 contains a patch for this issue. As a workaround, change line 29 of blob/master/src/crypto.js to include a regular expression.

CVSS v3
5.9
EG Score
5.9(medium)
EPSS
48.9%
KEV
Not listed

Published

November 20, 2023

Last Modified

June 17, 2026

References (6)

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
fast-jwt—3.3.2—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 47× 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.

Showing the most recent 100 of 101 total refreshes for this CVE.

  1. 2026-07-22 14:06 UTCEPSS rescore
  2. 2026-07-21 15:23 UTCEPSS rescore
  3. 2026-07-21 15:23 UTCEPSS rescore
  4. 2026-07-20 17:06 UTCEPSS rescore
  5. 2026-07-19 14:29 UTCEPSS rescore
  6. 2026-07-19 14:29 UTCEPSS rescore
  7. 2026-07-19 02:27 UTCEPSS rescore
  8. 2026-07-18 10:03 UTCEPSS rescore
  9. 2026-07-18 10:03 UTCEPSS rescore
  10. 2026-07-16 17:01 UTCEPSS rescore
  11. 2026-07-15 16:56 UTCEPSS rescore
  12. 2026-07-15 16:56 UTCEPSS rescore
  13. 2026-07-15 03:19 UTCOSV refresh
  14. 2026-07-15 01:59 UTCEPSS rescore
  15. 2026-07-15 01:59 UTCEPSS rescore
  16. 2026-07-13 22:28 UTCEPSS rescore
  17. 2026-07-13 22:28 UTCEPSS rescore
  18. 2026-07-13 06:11 UTCEPSS rescore
  19. 2026-07-13 06:11 UTCEPSS rescore
  20. 2026-07-12 05:45 UTCEPSS rescore
  21. 2026-07-11 08:26 UTCEPSS rescore
  22. 2026-07-09 19:08 UTCEPSS rescore
  23. 2026-07-08 15:13 UTCEPSS rescore
  24. 2026-07-07 13:44 UTCEPSS rescore
  25. 2026-07-07 13:44 UTCEPSS rescore
Show 75 more
  1. 2026-07-06 16:26 UTCEPSS rescore
  2. 2026-07-06 16:26 UTCEPSS rescore
  3. 2026-07-06 02:22 UTCEPSS rescore
  4. 2026-07-05 02:29 UTCEPSS rescore
  5. 2026-07-04 06:29 UTCEPSS rescore
  6. 2026-07-04 06:29 UTCEPSS rescore
  7. 2026-07-02 16:59 UTCEPSS rescore
  8. 2026-07-01 15:05 UTCEPSS rescore
  9. 2026-06-30 23:21 UTCEPSS rescore
  10. 2026-06-30 23:21 UTCEPSS rescore
  11. 2026-06-29 14:05 UTCEPSS rescore
  12. 2026-06-28 14:06 UTCEPSS rescore
  13. 2026-06-28 14:06 UTCEPSS rescore
  14. 2026-06-28 04:55 UTCEPSS rescore
  15. 2026-06-27 04:04 UTCOSV refresh
  16. 2026-06-27 03:07 UTCEPSS rescore
  17. 2026-06-25 13:48 UTCEPSS rescore
  18. 2026-06-25 13:48 UTCEPSS rescore
  19. 2026-06-24 14:04 UTCEPSS rescore
  20. 2026-06-24 14:04 UTCEPSS rescore
  21. 2026-06-23 21:31 UTCEPSS rescore
  22. 2026-06-23 21:31 UTCEPSS rescore
  23. 2026-06-22 14:24 UTCEPSS rescore
  24. 2026-06-22 14:24 UTCEPSS rescore
  25. 2026-06-21 14:55 UTCEPSS rescore
  26. 2026-06-21 14:55 UTCEPSS rescore
  27. 2026-06-21 01:58 UTCEPSS rescore
  28. 2026-06-21 01:58 UTCEPSS rescore
  29. 2026-06-19 19:24 UTCEPSS rescore
  30. 2026-06-19 19:24 UTCEPSS rescore
  31. 2026-06-18 17:51 UTCEPSS rescore
  32. 2026-06-17 17:51 UTCEPSS rescore
  33. 2026-06-16 17:51 UTCEPSS rescore
  34. 2026-06-16 17:51 UTCEPSS rescore
  35. 2026-06-15 17:47 UTCEPSS rescore
  36. 2026-06-14 23:16 UTCEPSS rescore
  37. 2026-06-13 22:59 UTCEPSS rescore
  38. 2026-06-13 22:59 UTCEPSS rescore
  39. 2026-06-12 23:11 UTCEPSS rescore
  40. 2026-06-12 23:10 UTCEPSS rescore
  41. 2026-06-11 13:59 UTCEPSS rescore
  42. 2026-06-10 22:17 UTCEPSS rescore
  43. 2026-06-10 13:21 UTCEPSS rescore
  44. 2026-06-09 14:47 UTCOSV refresh
  45. 2026-06-08 14:16 UTCEPSS rescore
  46. 2026-06-08 14:16 UTCEPSS rescore
  47. 2026-06-07 15:24 UTCEPSS rescore
  48. 2026-06-07 15:23 UTCEPSS rescore
  49. 2026-06-06 13:46 UTCEPSS rescore
  50. 2026-06-06 13:46 UTCEPSS rescore
  51. 2026-06-05 22:46 UTCEPSS rescore
  52. 2026-06-05 22:46 UTCEPSS rescore
  53. 2026-06-05 06:09 UTCEPSS rescore
  54. 2026-06-05 06:09 UTCEPSS rescore
  55. 2026-06-05 06:09 UTCEPSS rescore
  56. 2026-06-04 13:11 UTCEPSS rescore
  57. 2026-06-04 13:11 UTCEPSS rescore
  58. 2026-06-04 13:11 UTCEPSS rescore
  59. 2026-06-02 20:12 UTCEPSS rescore
  60. 2026-06-02 20:12 UTCEPSS rescore
  61. 2026-06-01 13:51 UTCEPSS rescore
  62. 2026-06-01 13:51 UTCEPSS rescore
  63. 2026-05-31 22:30 UTCEPSS rescore
  64. 2026-05-31 22:30 UTCEPSS rescore
  65. 2026-05-31 00:15 UTCEPSS rescore
  66. 2026-05-31 00:15 UTCEPSS rescore
  67. 2026-05-29 13:43 UTCEPSS rescore
  68. 2026-05-28 13:44 UTCEPSS rescore
  69. 2026-05-27 13:39 UTCEPSS rescore
  70. 2026-05-27 13:39 UTCEPSS rescore
  71. 2026-05-26 13:43 UTCEPSS rescore
  72. 2026-05-26 13:43 UTCEPSS rescore
  73. 2026-05-26 07:18 UTCEPSS rescore
  74. 2026-05-26 07:18 UTCEPSS rescore
  75. 2026-05-26 07:18 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2023-48223?
CVE-2023-48223 is a medium vulnerability published on November 20, 2023. fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to version 3.3.2, the fast-jwt library does not properly prevent JWT algorithm confusion for all public key types. The 'publicKeyPemMatcher' in 'fast-jwt/src/crypto.js' does not properly match all common PEM formats for public keys.…
When was CVE-2023-48223 disclosed?
CVE-2023-48223 was first published in the National Vulnerability Database on November 20, 2023, 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-2023-48223 actively exploited?
CVE-2023-48223 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 48.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2023-48223?
CVE-2023-48223 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2023-48223?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-48223, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-48223

Explore →

Is Your Infrastructure Affected by CVE-2023-48223?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs