CVE-2020-11996

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 26.7%, top 2% 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
Trending — 3 sources updated this weekElevated
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 27%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
54(Track)
EG Risk 54/100SSVC: Track

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
Severity75% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
97.8%
KEV
Not listed

Published

June 26, 2020

Last Modified

November 21, 2024

References (48)

Vendor Advisories for CVE-2020-11996(1)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntutomcat9-user (9.0.31-1ubuntu0.1) @ focal2026-05-27ubuntu
redhattomcat2021-08-11redhat
redhatpatch2021-01-07redhat
redhatjws5-tomcat-native-0:1.2.25-2.redhat_2.el8jws2020-11-23redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(2 across 1 ecosystem)
Maven(2)
PackageVulnerable rangeFixed inDependents
org.apache.tomcat.embed:tomcat-embed-core8.5.0 ... 8.5.9 (43 versions)8.5.55—
org.apache.tomcat:tomcat8.5.0 ... 8.5.9 (43 versions)8.5.55—

All Vendor Advisories

(6)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 12× in last 7d / 38× 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. 2026-07-23 01:48 UTCEG score recompute
  2. 2026-07-22 22:33 UTCEG score recompute
  3. 2026-07-22 14:05 UTCEPSS rescore
  4. 2026-07-21 15:22 UTCEPSS rescore
  5. 2026-07-21 15:22 UTCEPSS rescore
  6. 2026-07-20 17:04 UTCEPSS rescore
  7. 2026-07-19 10:22 UTCOSV refresh
  8. 2026-07-19 02:26 UTCEPSS rescore
  9. 2026-07-19 02:26 UTCEPSS rescore
  10. 2026-07-18 10:02 UTCEPSS rescore
  11. 2026-07-16 16:59 UTCEPSS rescore
  12. 2026-07-16 16:59 UTCEPSS rescore
  13. 2026-07-15 16:55 UTCEPSS rescore
  14. 2026-07-13 22:27 UTCEPSS rescore
  15. 2026-07-13 06:10 UTCEPSS rescore
  16. 2026-07-13 06:10 UTCEPSS rescore
  17. 2026-07-12 05:44 UTCEPSS rescore
  18. 2026-07-11 08:24 UTCEPSS rescore
  19. 2026-07-09 19:06 UTCEPSS rescore
  20. 2026-07-08 15:11 UTCEPSS rescore
  21. 2026-07-06 16:25 UTCEPSS rescore
  22. 2026-07-06 16:25 UTCEPSS rescore
  23. 2026-07-04 06:28 UTCEPSS rescore
  24. 2026-07-01 16:31 UTCOSV refresh
  25. 2026-07-01 15:03 UTCEPSS rescore
Show 62 more
  1. 2026-07-01 15:03 UTCEPSS rescore
  2. 2026-06-30 23:20 UTCEPSS rescore
  3. 2026-06-30 23:20 UTCEPSS rescore
  4. 2026-06-28 14:05 UTCEPSS rescore
  5. 2026-06-28 04:54 UTCEPSS rescore
  6. 2026-06-28 04:54 UTCEPSS rescore
  7. 2026-06-27 03:06 UTCEPSS rescore
  8. 2026-06-25 13:47 UTCEPSS rescore
  9. 2026-06-25 13:47 UTCEPSS rescore
  10. 2026-06-24 14:03 UTCEPSS rescore
  11. 2026-06-24 14:03 UTCEPSS rescore
  12. 2026-06-23 21:31 UTCEPSS rescore
  13. 2026-06-23 21:31 UTCEPSS rescore
  14. 2026-06-22 14:23 UTCEPSS rescore
  15. 2026-06-22 14:23 UTCEPSS rescore
  16. 2026-06-21 14:54 UTCEPSS rescore
  17. 2026-06-21 14:54 UTCEPSS rescore
  18. 2026-06-21 01:57 UTCEPSS rescore
  19. 2026-06-21 01:57 UTCEPSS rescore
  20. 2026-06-18 17:50 UTCEPSS rescore
  21. 2026-06-18 17:50 UTCEPSS rescore
  22. 2026-06-17 17:50 UTCEPSS rescore
  23. 2026-06-17 17:50 UTCEPSS rescore
  24. 2026-06-16 17:50 UTCEPSS rescore
  25. 2026-06-16 17:50 UTCEPSS rescore
  26. 2026-06-15 17:46 UTCEPSS rescore
  27. 2026-06-14 23:15 UTCEPSS rescore
  28. 2026-06-14 23:15 UTCEPSS rescore
  29. 2026-06-14 00:13 UTCOSV refresh
  30. 2026-06-13 22:58 UTCEPSS rescore
  31. 2026-06-13 22:58 UTCEPSS rescore
  32. 2026-06-12 23:09 UTCEPSS rescore
  33. 2026-06-11 13:58 UTCEPSS rescore
  34. 2026-06-10 22:16 UTCEPSS rescore
  35. 2026-06-10 22:16 UTCEPSS rescore
  36. 2026-06-10 13:20 UTCEPSS rescore
  37. 2026-06-08 14:15 UTCEPSS rescore
  38. 2026-06-08 14:15 UTCEPSS rescore
  39. 2026-06-06 13:45 UTCEPSS rescore
  40. 2026-06-06 13:45 UTCEPSS rescore
  41. 2026-06-06 13:45 UTCEPSS rescore
  42. 2026-06-05 22:45 UTCEPSS rescore
  43. 2026-06-05 22:45 UTCEPSS rescore
  44. 2026-06-05 06:08 UTCEPSS rescore
  45. 2026-06-04 13:10 UTCEPSS rescore
  46. 2026-06-04 13:10 UTCEPSS rescore
  47. 2026-06-02 20:11 UTCEPSS rescore
  48. 2026-06-02 20:11 UTCEPSS rescore
  49. 2026-06-01 13:50 UTCEPSS rescore
  50. 2026-05-31 22:29 UTCEPSS rescore
  51. 2026-05-31 22:29 UTCEPSS rescore
  52. 2026-05-31 00:15 UTCEPSS rescore
  53. 2026-05-31 00:14 UTCEPSS rescore
  54. 2026-05-29 13:42 UTCEPSS rescore
  55. 2026-05-29 13:42 UTCEPSS rescore
  56. 2026-05-28 13:43 UTCEPSS rescore
  57. 2026-05-28 13:43 UTCEPSS rescore
  58. 2026-05-27 13:39 UTCEPSS rescore
  59. 2026-05-27 01:54 UTCEG score recompute
  60. 2026-05-27 01:54 UTCVendor advisory
  61. 2026-05-26 07:17 UTCEPSS rescore
  62. 2026-05-26 07:17 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCrusakovichma/tomcat-embed-core-9.0.31-CVE-2020-11996
    First seen Jul 27, 2020

    tomcat-embed-core-9.0.31 CVE-2020-11996 Test PoC

    Open source ↗

Related CVEs(same vendor)

Frequently asked(5)

What is CVE-2020-11996?
CVE-2020-11996 is a high vulnerability published on June 26, 2020. A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become…
When was CVE-2020-11996 disclosed?
CVE-2020-11996 was first published in the National Vulnerability Database on June 26, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-11996 actively exploited?
CVE-2020-11996 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 97.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-11996?
CVE-2020-11996 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2020-11996?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-11996, 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.

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