CVE-2026-45019

HIGHPre-NVD 7.27.2
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 7.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (35th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
7.2EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.2Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Chainlit is a Python framework for building production-ready conversational AI applications. From 2.4.0rc0 until 2.12.0, Chainlit deployments with features.mcp.enabled set to true in .chainlit/config.toml expose the POST /mcp endpoint without requiring authentication. For sse and streamable-http transports, ConnectSseMCPRequest and ConnectStreamableHttpMCPRequest in backend/chainlit/types.py accept a user-controlled url and optional headers dictionary without scheme validation, private-address filtering, or an allowlist. The connect_mcp handler in backend/chainlit/server.py passes these values to sse_client() or streamablehttp_client(), allowing the Chainlit server to make blind outbound requests to arbitrary internal or external services, including cloud metadata endpoints, with attacker-controlled Authorization and Cookie headers. The SSE URL sink has existed since 2.4.0rc0, while attacker-controlled header forwarding and streamable-http support were added in 2.6.4. The response is consumed internally and not returned, but the attacker can issue state-changing authenticated requests, discover internal services, scan ports, and probe metadata endpoints. This issue is fixed in version 2.12.0.

CVSS v3
7.2
EG Score
7.2HIGHmedium confidence
EG Risk
48
EG Risk 48/100

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 (value × EchelonGraph’s weight)
Severity72% × 45%
The EG Score, 7.2 of 10.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
35th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 25, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Aug 25, 2026
Patch available. Sources: github, github_release.
GitHub release Patch Available

2.12.0

Patch available: Chainlit/chainlit 2.12.0

https://github.com/Chainlit/chainlit/releases/tag/2.12.0
Web page

chainlit/docs/security-advisory-2026-mcp.md at 2.12.0 · Chainlit/chainlit · GitHub

https://github.com/Chainlit/chainlit/blob/2.12.0/docs/security-advisory-2026-mcp.md#spl-2026-002--ssrf-via-mcp-streamable-http--sse
GitHub advisoryMentions a patch (unverified)

SSRF via MCP SSE and streamable-http transports allows unauthenticated internal network access · Advisory · Chainlit/chainlit · GitHub

https://github.com/Chainlit/chainlit/security/advisories/GHSA-hvfh-5mj3-5f3j

Vendor Advisories for CVE-2026-45019(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)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
chainlit2.10.0 ... 2.9.6 (41 versions)
  • 2.4.0rc0 up to 2.12.0: fixed in 2.12.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 50× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  3. 2026-10-12 16:04 UTCEG score recompute
  4. 2026-10-11 19:47 UTCEG score recompute
  5. 2026-10-11 17:01 UTCEG score recompute
  6. 2026-10-11 14:26 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  9. 2026-10-10 11:42 UTCEG score recompute
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  11. 2026-10-09 04:08 UTCEG score recompute
  12. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  13. 2026-10-08 02:52 UTCEG score recompute
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  15. 2026-10-06 19:18 UTCEG score recompute
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  17. 2026-10-06 07:42 UTCEG score recompute
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  19. 2026-10-05 03:57 UTCEG score recompute
  20. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  21. 2026-10-03 17:42 UTCEG score recompute
  22. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-10-02 18:53 UTCEG score recompute
  24. 2026-10-01 20:01 UTCEG score recompute
  25. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 35th percentile
Show 63 more
  1. 2026-09-30 20:14 UTCEG score recompute
  2. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  3. 2026-09-30 06:41 UTCEG score recompute
  4. 2026-09-29 08:52 UTCEG score recompute
  5. 2026-09-28 21:28 UTCEG score recompute
  6. 2026-09-27 20:56 UTCEG score recompute
  7. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  8. 2026-09-26 21:58 UTCEG score recompute
  9. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  10. 2026-09-24 17:00 UTCEG score recompute
  11. 2026-09-23 18:11 UTCEG score recompute
  12. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  13. 2026-09-22 19:22 UTCEG score recompute
  14. 2026-09-22 07:52 UTCEG score recompute
  15. 2026-09-20 21:01 UTCEG score recompute
  16. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  17. 2026-09-19 22:11 UTCEG score recompute
  18. 2026-09-18 23:20 UTCEG score recompute
  19. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  20. 2026-09-18 00:32 UTCEG score recompute
  21. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  22. 2026-09-16 14:13 UTCEG score recompute
  23. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  24. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  25. 2026-09-15 14:29 UTCEG score recompute
  26. 2026-09-13 16:51 UTCEG score recompute
  27. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  28. 2026-09-12 18:01 UTCEG score recompute
  29. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  30. 2026-09-11 19:11 UTCEG score recompute
  31. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  32. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  33. 2026-09-10 20:07 UTCEG score recompute
  34. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  35. 2026-09-09 01:11 UTCEG score recompute
  36. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  37. 2026-09-07 17:15 UTCEG score recompute
  38. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  39. 2026-09-06 18:26 UTCEG score recompute
  40. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  41. 2026-09-05 19:36 UTCEG score recompute
  42. 2026-09-04 20:47 UTCEG score recompute
  43. 2026-09-04 08:48 UTCEG score recompute
  44. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  45. 2026-09-02 22:31 UTCEG score recompute
  46. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  47. 2026-09-01 23:23 UTCEG score recompute
  48. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  49. 2026-09-01 11:58 UTCEG score recompute
  50. 2026-08-31 01:39 UTCEG score recompute
  51. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  52. 2026-08-30 02:49 UTCEG score recompute
  53. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  54. 2026-08-29 03:57 UTCEG score recompute
  55. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  56. 2026-08-27 17:34 UTCEG score recompute
  57. 2026-08-27 17:11 UTCEG score recompute
  58. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  59. 2026-08-26 19:13 UTCEG score recompute
  60. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  61. 2026-08-25 20:23 UTCEG score recompute
  62. 2026-08-25 19:35 UTCEG score recomputeFirst assessed: 7.2 HIGH
  63. 2026-08-25 19:34 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-45019?
CVE-2026-45019 is a high-severity vulnerability; its CVE record was published on August 25, 2026. Chainlit is a Python framework for building production-ready conversational AI applications. From 2.4.0rc0 until 2.12.0, Chainlit deployments with features.mcp.enabled set to true in .chainlit/config.toml expose the POST /mcp endpoint without requiring authentication. For sse and streamable-http…
When was the CVE record for CVE-2026-45019 published?
The CVE record for CVE-2026-45019 was published on August 25, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 9, 2026; the record at its source may have been updated since.
Is CVE-2026-45019 actively exploited?
CVE-2026-45019 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-45019?
CVE-2026-45019 has a CVSS base score of 7.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-45019?
A fix for CVE-2026-45019 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-45019 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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