CVE-2026-56104

HIGHPre-NVD 8.27.4▼
EchelonGraph scoreHIGH confidence

Score 7.4 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-22. a secondary CVSS source baseline 8.2; sources differ by 0.8.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.2
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.2Exploit: NoneExposed: 0

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

Chainlit before 2.10.1 contains a session hijacking vulnerability that allows unauthenticated attackers to restore and inherit authenticated user sessions by presenting a valid sessionId during WebSocket session restoration without ownership verification. Attackers can exploit the restore_existing_session path to assume a victim's permissions and roles, enabling unauthorized invocation of tools and access to data restricted to the authenticated victim.

CVSS v3
8.2
EG Score
7.4(high)
EPSS
17.0%
KEV
Not listed

Published

June 22, 2026

Last Modified

June 23, 2026

Advisory Details (4)

Auto-updated Jun 22, 2026
Patch available. Sources: github_commit, github_pr, github_release.
generic

Chainlit < 2.10.1 Session Hijacking via WebSocket Session Restoration | Advisories | VulnCheck

https://www.vulncheck.com/advisories/chainlit-session-hijacking-via-websocket-session-restoration
github_release Patch Available

2.10.1

Patch available: Chainlit/chainlit 2.10.1

https://github.com/Chainlit/chainlit/releases/tag/2.10.1
github_pr Patch Available

fix: validate session ownership on websocket restore

Patch available: Chainlit/chainlit 2.10.1 (PR #2857 merged 2026-03-24)

https://github.com/Chainlit/chainlit/pull/2857
github_commit Patch Available

commit 5effb664f1e0 (Chainlit/chainlit)

Patch available: Chainlit/chainlit 2.10.1 (contains commit 5effb664f1e0)

https://github.com/Chainlit/chainlit/commit/5effb664f1e0af4a4f0a42fe63ea979676039a7f

Vendor Advisories for CVE-2026-56104(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 38× in last 7d / 81× 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. 2026-07-06 23:09 UTCEG score recompute
  2. 2026-07-06 23:09 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 11:26 UTCEG score recompute
  6. 2026-07-06 11:26 UTCGHSA enrichment
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-06 02:23 UTCEPSS rescore
  9. 2026-07-05 23:39 UTCEG score recompute
  10. 2026-07-05 23:39 UTCGHSA enrichment
  11. 2026-07-05 11:57 UTCEG score recompute
  12. 2026-07-05 11:56 UTCGHSA enrichment
  13. 2026-07-05 02:31 UTCEPSS rescore
  14. 2026-07-05 02:30 UTCEPSS rescore
  15. 2026-07-05 00:14 UTCEG score recompute
  16. 2026-07-05 00:13 UTCGHSA enrichment
  17. 2026-07-04 12:29 UTCEG score recompute
  18. 2026-07-04 12:29 UTCGHSA enrichment
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-04 06:31 UTCEPSS rescore
  21. 2026-07-04 00:47 UTCEG score recompute
  22. 2026-07-04 00:47 UTCGHSA enrichment
  23. 2026-07-03 12:55 UTCEG score recompute
  24. 2026-07-03 12:55 UTCGHSA enrichment
  25. 2026-07-03 00:03 UTCEG score recompute
Show 56 more
  1. 2026-07-03 00:03 UTCGHSA enrichment
  2. 2026-07-02 12:19 UTCEG score recompute
  3. 2026-07-02 12:19 UTCGHSA enrichment
  4. 2026-07-02 00:37 UTCEG score recompute
  5. 2026-07-02 00:37 UTCGHSA enrichment
  6. 2026-07-01 15:07 UTCEPSS rescore
  7. 2026-07-01 12:54 UTCEG score recompute
  8. 2026-07-01 12:54 UTCGHSA enrichment
  9. 2026-07-01 01:12 UTCEG score recompute
  10. 2026-07-01 01:12 UTCGHSA enrichment
  11. 2026-06-30 23:22 UTCEPSS rescore
  12. 2026-06-30 13:29 UTCEG score recompute
  13. 2026-06-30 13:29 UTCGHSA enrichment
  14. 2026-06-30 01:46 UTCEG score recompute
  15. 2026-06-30 01:46 UTCGHSA enrichment
  16. 2026-06-29 14:06 UTCEPSS rescore
  17. 2026-06-29 14:06 UTCEPSS rescore
  18. 2026-06-29 14:03 UTCEG score recompute
  19. 2026-06-29 14:03 UTCGHSA enrichment
  20. 2026-06-29 02:21 UTCEG score recompute
  21. 2026-06-29 02:21 UTCGHSA enrichment
  22. 2026-06-28 14:38 UTCEG score recompute
  23. 2026-06-28 14:38 UTCGHSA enrichment
  24. 2026-06-28 14:07 UTCEPSS rescore
  25. 2026-06-28 04:56 UTCEPSS rescore
  26. 2026-06-28 04:56 UTCEPSS rescore
  27. 2026-06-28 02:56 UTCEG score recompute
  28. 2026-06-28 02:56 UTCGHSA enrichment
  29. 2026-06-27 15:13 UTCEG score recompute
  30. 2026-06-27 15:13 UTCGHSA enrichment
  31. 2026-06-27 03:30 UTCEG score recompute
  32. 2026-06-27 03:30 UTCGHSA enrichment
  33. 2026-06-27 03:08 UTCEPSS rescore
  34. 2026-06-26 15:36 UTCEG score recompute
  35. 2026-06-26 15:35 UTCGHSA enrichment
  36. 2026-06-26 03:52 UTCEG score recompute
  37. 2026-06-26 03:52 UTCGHSA enrichment
  38. 2026-06-25 16:09 UTCEG score recompute
  39. 2026-06-25 16:09 UTCGHSA enrichment
  40. 2026-06-25 13:49 UTCEPSS rescore
  41. 2026-06-25 04:27 UTCEG score recompute
  42. 2026-06-25 04:27 UTCGHSA enrichment
  43. 2026-06-24 16:42 UTCEG score recompute
  44. 2026-06-24 16:41 UTCGHSA enrichment
  45. 2026-06-24 14:05 UTCEPSS rescore
  46. 2026-06-24 04:59 UTCEG score recompute
  47. 2026-06-24 04:59 UTCGHSA enrichment
  48. 2026-06-23 21:33 UTCEPSS rescore
  49. 2026-06-23 21:33 UTCEPSS rescore
  50. 2026-06-23 17:32 UTCNVD updateCVSS v3 → 8.2 · CVSS v4 → 8.8
  51. 2026-06-23 17:16 UTCEG score recompute
  52. 2026-06-23 17:16 UTCGHSA enrichment
  53. 2026-06-23 05:31 UTCEG score recompute
  54. 2026-06-23 05:31 UTCGHSA enrichment
  55. 2026-06-22 17:47 UTCEG score recompute
  56. 2026-06-22 17:45 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-56104?
CVE-2026-56104 is a high vulnerability published on June 22, 2026. Chainlit before 2.10.1 contains a session hijacking vulnerability that allows unauthenticated attackers to restore and inherit authenticated user sessions by presenting a valid sessionId during WebSocket session restoration without ownership verification. Attackers can exploit the…
When was CVE-2026-56104 disclosed?
CVE-2026-56104 was first published in the National Vulnerability Database on June 22, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56104 actively exploited?
CVE-2026-56104 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 17.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56104?
CVE-2026-56104 has a CVSS v3 base score of 8.2 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.4.
How do I remediate CVE-2026-56104?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56104, 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

Explore the affected products and dependency analysis for CVE-2026-56104

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