CVE-2026-44214

MEDIUMNVD 5.85.8—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.8 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 81% 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
Elevated
5.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.8Exploit: NoneExposed: 0

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

eventsource-encoder encodes events as well-formed EventSource/Server Sent Event (SSE) messages. Prior to 1.0.2, eventsource-encoder does not sanitize the event or id fields of an EventSourceMessage before serializing them. An attacker who controls either field can inject arbitrary Server-Sent Events line terminators (\n, \r, or \r\n) and thereby forge additional SSE fields or entire messages on the stream. This vulnerability is fixed in 1.0.2.

CVSS v3
5.8
EG Score
5.8(medium)
EPSS
19.5%
KEV
Not listed

Published

May 26, 2026

Last Modified

May 28, 2026

Advisory Details (1)

Auto-updated Jun 14, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

SSE event injection via unsanitized `event` and `id` fields · Advisory · rexxars/eventsource-encoder · GitHub

https://github.com/rexxars/eventsource-encoder/security/advisories/GHSA-m9g3-3g99-mhpx

Vendor Advisories for CVE-2026-44214(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
eventsource-encoder—1.0.2—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 42× 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. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-07 13:46 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-05 02:30 UTCEPSS rescore
  7. 2026-07-01 15:07 UTCEPSS rescore
  8. 2026-07-01 12:12 UTCEG score recompute
  9. 2026-06-30 23:22 UTCEPSS rescore
  10. 2026-06-29 23:14 UTCEG score recompute
  11. 2026-06-29 14:06 UTCEPSS rescore
  12. 2026-06-28 22:48 UTCEG score recompute
  13. 2026-06-28 14:07 UTCEPSS rescore
  14. 2026-06-28 04:56 UTCEPSS rescore
  15. 2026-06-27 18:51 UTCEG score recompute
  16. 2026-06-27 03:08 UTCEPSS rescore
  17. 2026-06-26 17:31 UTCEG score recompute
  18. 2026-06-25 13:49 UTCEPSS rescore
  19. 2026-06-25 13:49 UTCEPSS rescore
  20. 2026-06-25 11:17 UTCEG score recompute
  21. 2026-06-24 14:05 UTCEPSS rescore
  22. 2026-06-23 21:33 UTCEPSS rescore
  23. 2026-06-22 14:25 UTCEPSS rescore
  24. 2026-06-22 14:25 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
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  1. 2026-06-21 14:56 UTCEPSS rescore
  2. 2026-06-21 01:59 UTCEPSS rescore
  3. 2026-06-19 19:25 UTCEPSS rescore
  4. 2026-06-18 17:52 UTCEPSS rescore
  5. 2026-06-18 17:52 UTCEPSS rescore
  6. 2026-06-17 17:53 UTCEPSS rescore
  7. 2026-06-17 09:56 UTCEG score recompute
  8. 2026-06-16 17:52 UTCEPSS rescore
  9. 2026-06-16 08:17 UTCEG score recompute
  10. 2026-06-15 17:49 UTCEPSS rescore
  11. 2026-06-15 07:49 UTCEG score recompute
  12. 2026-06-14 07:25 UTCEG score recompute
  13. 2026-06-13 23:00 UTCEPSS rescore
  14. 2026-06-13 07:00 UTCEG score recompute
  15. 2026-06-12 23:12 UTCEPSS rescore
  16. 2026-06-12 23:12 UTCEPSS rescore
  17. 2026-06-12 06:34 UTCEG score recompute
  18. 2026-06-11 14:00 UTCEPSS rescore
  19. 2026-06-11 06:09 UTCEG score recompute
  20. 2026-06-10 22:18 UTCEPSS rescore
  21. 2026-06-10 13:22 UTCEPSS rescore
  22. 2026-06-10 13:22 UTCEPSS rescore
  23. 2026-06-10 05:44 UTCEG score recompute
  24. 2026-06-09 05:20 UTCEG score recompute
  25. 2026-06-08 14:17 UTCEPSS rescore
  26. 2026-06-08 14:17 UTCEPSS rescore
  27. 2026-06-08 04:54 UTCEG score recompute
  28. 2026-06-07 15:25 UTCEPSS rescore
  29. 2026-06-07 15:25 UTCEPSS rescore
  30. 2026-06-07 04:30 UTCEG score recompute
  31. 2026-06-06 13:47 UTCEPSS rescore
  32. 2026-06-06 13:47 UTCEPSS rescore
  33. 2026-06-06 04:05 UTCEG score recompute
  34. 2026-06-05 22:47 UTCEPSS rescore
  35. 2026-06-05 06:10 UTCEPSS rescore
  36. 2026-06-05 06:10 UTCEPSS rescore
  37. 2026-06-05 03:40 UTCEG score recompute
  38. 2026-06-04 13:12 UTCEPSS rescore
  39. 2026-06-04 13:12 UTCEPSS rescore
  40. 2026-06-04 03:15 UTCEG score recompute
  41. 2026-06-03 02:50 UTCEG score recompute
  42. 2026-06-02 20:13 UTCEPSS rescore
  43. 2026-06-02 02:25 UTCEG score recompute
  44. 2026-06-01 13:52 UTCEPSS rescore
  45. 2026-06-01 13:52 UTCEPSS rescore
  46. 2026-06-01 02:00 UTCEG score recompute
  47. 2026-05-31 22:30 UTCEPSS rescore
  48. 2026-05-31 22:30 UTCEPSS rescore
  49. 2026-05-31 00:16 UTCEPSS rescore
  50. 2026-05-31 00:16 UTCEPSS rescore
  51. 2026-05-29 13:44 UTCEPSS rescore
  52. 2026-05-29 13:44 UTCEPSS rescore
  53. 2026-05-28 13:44 UTCEPSS rescore
  54. 2026-05-28 13:44 UTCEPSS rescore
  55. 2026-05-27 13:40 UTCEPSS rescore
  56. 2026-05-27 13:40 UTCEPSS rescore
  57. 2026-05-26 19:39 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-44214?
CVE-2026-44214 is a medium vulnerability published on May 26, 2026. eventsource-encoder encodes events as well-formed EventSource/Server Sent Event (SSE) messages. Prior to 1.0.2, eventsource-encoder does not sanitize the event or id fields of an EventSourceMessage before serializing them. An attacker who controls either field can inject arbitrary Server-Sent…
When was CVE-2026-44214 disclosed?
CVE-2026-44214 was first published in the National Vulnerability Database on May 26, 2026, with the most recent update on May 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-44214 actively exploited?
CVE-2026-44214 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 19.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-44214?
CVE-2026-44214 has a CVSS v3 base score of 5.8 (NVD).
How do I remediate CVE-2026-44214?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-44214, 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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