CVE-2016-6816

HIGHNVD 7.17.1
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 under NVD CVSS v3. EPSS exploit probability: 39.6%, 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
Elevated
7.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 40%CVSS: 7.1Exploit: NoneExposed: 0

A fix is available — apply it.

The code in Apache Tomcat 9.0.0.M1 to 9.0.0.M11, 8.5.0 to 8.5.6, 8.0.0.RC1 to 8.0.38, 7.0.0 to 7.0.72, and 6.0.0 to 6.0.47 that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack and/or obtain sensitive information from requests other then their own.

CVSS v3
7.1
EG Score
7.1(medium)
EPSS
98.5%
KEV
Not listed

Published

March 20, 2017

Last Modified

May 13, 2026

Patch Availability(12)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntutomcat8 (8.0.37-1ubuntu0.1) @ yakkety2026-05-22ubuntu
ubuntulibservlet2.5-java-doc (6.0.45+dfsg-1ubuntu0.1) @ xenial2026-05-22ubuntu
redhattomcat-0:7.0.69-11.el7_32017-04-12redhat
redhattomcat6-0:6.0.24-105.el6_82017-03-15redhat
redhatpatch2017-03-07redhat
redhattomcat-vault-0:1.0.8-9.Final_redhat_2.1.ep7.el62017-03-07redhat
redhattomcat-vault-0:1.0.8-9.Final_redhat_2.1.ep7.el72017-03-07redhat
redhatresteasy-0:2.3.16-1.Final_redhat_1.1.ep6.el52017-02-02redhat
redhatresteasy-0:2.3.16-1.Final_redhat_1.1.ep6.el62017-02-02redhat
redhatresteasy-0:2.3.16-1.Final_redhat_1.1.ep6.el72017-02-02redhat
redhatpatch2017-02-02redhat
redhatjboss-ec2-eap-0:7.5.13-1.Final_redhat_2.ep6.el62017-02-02redhat

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

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
org.apache.tomcat:tomcat-coyote6.0.48

All Vendor Advisories

(12)

Data Freshness Timeline

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

Publicly available exploits

(1 reference)

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

  • Exploit-DBEDB-41783
    First seen Apr 4, 2017

    Apache Tomcat 6/7/8/9 - Information Disclosure

    Open source ↗

Frequently asked(5)

What is CVE-2016-6816?
CVE-2016-6816 is a high vulnerability published on March 20, 2017. The code in Apache Tomcat 9.0.0.M1 to 9.0.0.M11, 8.5.0 to 8.5.6, 8.0.0.RC1 to 8.0.38, 7.0.0 to 7.0.72, and 6.0.0 to 6.0.47 that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a…
When was CVE-2016-6816 disclosed?
CVE-2016-6816 was first published in the National Vulnerability Database on March 20, 2017, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-6816 actively exploited?
CVE-2016-6816 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2016-6816?
CVE-2016-6816 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2016-6816?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-6816, 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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