CVE-2026-77357

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (43rd percentile of EPSS-scored CVEs). 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, secondary
Elevated
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.7Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

Mesop is a Python-based UI framework that allows users to build web applications. Prior to 1.3.3, applications running in debug mode expose a GET /hot-reload endpoint whose unbounded loop depends on the user-supplied counter parameter, allowing an unauthenticated attacker to hold worker threads with high counter values until the worker pool is exhausted and the server becomes unavailable. A single unauthenticated attacker can crash the Mesop server with minimal effort. Because the attack leverages worker exhaustion, the server remains unresponsive until it is manually restarted. This issue is fixed in version 1.3.3.

CVSS v3
8.7
EG Score
8.7HIGHmedium confidence
EG Risk
70
EG Risk 70/100CISA SSVC

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
Severity87% × 45%
Exploitation40% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
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
0.5%
EPSS %ILE
43rd
KEV
Not listed

CISA SSVCTrack 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 public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 25, 2026

Last Modified

September 9, 2026

Advisory Details (3)

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

v1.3.3

Patch available: mesop-dev/mesop v1.3.3

https://github.com/mesop-dev/mesop/releases/tag/v1.3.3
github_commit Patch Available

commit 2b8e7f2c349c (mesop-dev/mesop)

Patch available: mesop-dev/mesop v1.3.3 (contains commit 2b8e7f2c349c)

https://github.com/mesop-dev/mesop/commit/2b8e7f2c349c9e2eec202f46b07bada83061ce2d
githubMentions a patch (unverified)

Denial of Service in /__hot-reload__ endpoint allows unauthenticated attacker to exhaust worker threads and crash the server · Advisory · mesop-dev/mesop · GitHub

https://github.com/mesop-dev/mesop/security/advisories/GHSA-8p72-497j-83mx

Weakness Classification(2)

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

Data Freshness Timeline

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-77357?
CVE-2026-77357 is a high vulnerability published on August 25, 2026. Mesop is a Python-based UI framework that allows users to build web applications. Prior to 1.3.3, applications running in debug mode expose a GET /hot-reload endpoint whose unbounded loop depends on the user-supplied counter parameter, allowing an unauthenticated attacker to hold worker threads…
When was CVE-2026-77357 disclosed?
CVE-2026-77357 was first published on August 25, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77357 actively exploited?
CVE-2026-77357 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77357?
CVE-2026-77357 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-77357?
A fix for CVE-2026-77357 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-77357

Explore →

Is Your Infrastructure Affected by CVE-2026-77357?

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

Book a Demo →Browse All CVEs