CVE-2009-0580

MEDIUMCVSS v2 · 4.34.3—
EchelonGraph scoreLOW confidence

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 4.3 — v2 rates that MEDIUM (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:M/Au:N/C:P/I:N/A:N. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 94.4% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.

Sources: epss, nvd_v2
Trending — 3 sources updated this weekWeaponized
4.3EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • 79 internet-exposed hosts are running an affected version right now
  • High exploitation likelihood — EPSS 94%
  • Public exploit code is available (Metasploit, Exploit-DB (verified), epss top5pct, epss high, public exploit)
CISA-KEV: Not listedEPSS PROB: 94%CVSS v2: 4.3Exploit: Metasploit · Exploit-DB (verified) · epss top5pct · epss high · public exploitExposed: 79

A fix is available — apply it.

Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18, when FORM authentication is used, allows remote attackers to enumerate valid usernames via requests to /j_security_check with malformed URL encoding of passwords, related to improper error checking in the (1) MemoryRealm, (2) DataSourceRealm, and (3) JDBCRealm authentication realms, as demonstrated by a % (percent) value for the j_password parameter.

Live · internet exposure

79 internet-exposed hosts are running an affected version of CVE-2009-0580 right now.

across 22 countries (United States, China, Germany, Singapore, Hong Kong)top: tomcat
See the live KEV-Exposure radar →Found passively from public internet-scan data — aggregate, host-redacted.

EchelonGraph is the only CVE feed that fuses live vulnerability intelligence with its own live internet-exposure radar — so you see not just that a CVE is exploited, but how much of the internet is exposed to it right now.

CVSS v2.0 (legacy)
4.3MEDIUMNVD never assigned a CVSS v3 rating to this CVE
EG Score
4.3(low)
EG Risk
62(Track)
EG Risk 62/100SSVC: 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
Severity43% × 45%
Exploitation94% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
94%
EPSS %ILE
100%
KEV
Not listed

Published

June 5, 2009

Last Modified

April 23, 2026

References (98)

Vendor Advisories for CVE-2009-0580(1)

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

Patch Availability(10)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntutomcat6-examples (6.0.18-0ubuntu6.1) @ jaunty2026-07-23ubuntu
redhatxml-commons-0:1.3.02-2jpp_1rh2010-08-04redhat
redhattomcat5-0:5.5.23-0jpp_18rh2009-11-30redhat
redhattomcat5-0:5.5.23-0jpp_4rh.162009-11-09redhat
redhattomcat6-0:6.0.18-12.0.ep5.el52009-10-14redhat
redhattomcat5-0:5.5.23-0jpp.9.6.ep5.el52009-09-21redhat
redhattomcat5-0:5.5.23-0jpp.7.el5_3.22009-07-21redhat
redhatxerces-j2-0:2.7.1-9jpp.ep1.2.el42009-07-06redhat
redhatrh-eap-docs-0:4.3.0-5.GA_CP05.ep1.2.1.el52009-07-06redhat
redhatrh-eap-docs-0:4.2.0-5.GA_CP07.ep1.1.1.el52009-07-06redhat

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—6.0.19—

Additional Vendor Advisories

(11)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 32× in last 7d / 35× 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. 2026-07-26 13:37 UTCEG score recompute▲ 4.30
  2. 2026-07-23 14:14 UTCEPSS rescore
  3. 2026-07-23 01:05 UTCVendor advisory
  4. 2026-07-23 01:04 UTCVendor advisory
  5. 2026-07-23 01:03 UTCVendor advisory
  6. 2026-07-23 01:03 UTCVendor advisory
  7. 2026-07-23 01:02 UTCVendor advisory
  8. 2026-07-23 01:01 UTCVendor advisory
  9. 2026-07-23 00:59 UTCVendor advisory
  10. 2026-07-23 00:58 UTCVendor advisory
  11. 2026-07-23 00:57 UTCVendor advisory
  12. 2026-07-23 00:56 UTCVendor advisory
  13. 2026-07-23 00:55 UTCVendor advisory
  14. 2026-07-23 00:54 UTCVendor advisory
  15. 2026-07-23 00:53 UTCVendor advisory
  16. 2026-07-23 00:52 UTCVendor advisory
  17. 2026-07-23 00:51 UTCVendor advisory
  18. 2026-07-23 00:50 UTCVendor advisory
  19. 2026-07-23 00:49 UTCVendor advisory
  20. 2026-07-23 00:48 UTCVendor advisory
  21. 2026-07-23 00:47 UTCVendor advisory
  22. 2026-07-23 00:46 UTCVendor advisory
  23. 2026-07-23 00:44 UTCVendor advisory
  24. 2026-07-23 00:43 UTCVendor advisory
  25. 2026-07-23 00:43 UTCVendor advisory
Show 46 more
  1. 2026-07-23 00:42 UTCEG score recompute
  2. 2026-07-23 00:42 UTCVendor advisory
  3. 2026-07-23 00:40 UTCVendor advisory
  4. 2026-07-23 00:38 UTCVendor advisory
  5. 2026-07-23 00:36 UTCEG score recompute▼ 9.00
  6. 2026-07-23 00:03 UTCEG score recompute
  7. 2026-07-22 21:42 UTCEG score recompute
  8. 2026-07-18 09:59 UTCEPSS rescore
  9. 2026-07-01 15:02 UTCEPSS rescore
  10. 2026-06-30 23:19 UTCEPSS rescore
  11. 2026-06-25 13:46 UTCEPSS rescore
  12. 2026-06-25 13:46 UTCEPSS rescore
  13. 2026-06-23 21:29 UTCEPSS rescore
  14. 2026-06-23 21:29 UTCEPSS rescore
  15. 2026-06-18 17:49 UTCEPSS rescore
  16. 2026-06-18 17:49 UTCEPSS rescore
  17. 2026-06-15 17:44 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. 2026-06-10 22:14 UTCEPSS rescore
  22. 2026-06-10 13:17 UTCEPSS rescore
  23. 2026-06-07 15:22 UTCEPSS rescore
  24. 2026-06-07 15:22 UTCEPSS rescore
  25. 2026-06-06 13:44 UTCEPSS rescore
  26. 2026-06-06 13:44 UTCEPSS rescore
  27. 2026-06-06 13:44 UTCEPSS rescore
  28. 2026-06-05 22:44 UTCEPSS rescore
  29. 2026-06-05 22:44 UTCEPSS rescore
  30. 2026-06-05 06:07 UTCEPSS rescore
  31. 2026-05-30 16:39 UTCEG score recompute
  32. 2026-05-30 16:39 UTCVendor advisory
  33. 2026-05-29 13:40 UTCEPSS rescore
  34. 2026-05-28 13:42 UTCEPSS rescore
  35. 2026-05-28 13:42 UTCEPSS rescore
  36. 2026-05-28 13:42 UTCEPSS rescore
  37. 2026-05-26 13:41 UTCEPSS rescore
  38. 2026-05-26 13:41 UTCEPSS rescore
  39. 2026-05-26 07:16 UTCEPSS rescore
  40. 2026-05-26 07:16 UTCEPSS rescore
  41. 2026-05-24 16:43 UTCEPSS rescore
  42. 2026-05-22 21:15 UTCEPSS rescore
  43. 2026-05-22 21:15 UTCEPSS rescore
  44. 2026-05-20 22:37 UTCEPSS rescore
  45. 2026-05-20 22:37 UTCEPSS rescore
  46. 2026-05-18 21:29 UTCEPSS rescore

Publicly available exploits

(2 references)

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

  • Exploit-DBEDB-33023✓ verified
    First seen Jun 3, 2009

    Apache Tomcat 6.0.18 - Form Authentication Existing/Non-Existing 'Username' Enumeration

    Open source ↗
  • Metasploitauxiliary/scanner/http/tomcat_enum✓ verified
    First seen Jan 1, 2009

    Apache Tomcat User Enumeration

    Open source ↗

Frequently asked(4)

What is CVE-2009-0580?
CVE-2009-0580 is a medium vulnerability published on June 5, 2009. Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18, when FORM authentication is used, allows remote attackers to enumerate valid usernames via requests to /jsecuritycheck with malformed URL encoding of passwords, related to improper error checking in the (1)…
When was CVE-2009-0580 disclosed?
CVE-2009-0580 was first published in the National Vulnerability Database on June 5, 2009, with the most recent update on April 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2009-0580 actively exploited?
CVE-2009-0580 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 94% probability of exploitation in the next 30 days, which ranks it in the top 0.2% of all scored CVEs.
How do I remediate CVE-2009-0580?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2009-0580, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2009-0580

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