CVE-2016-4437

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, nvd
Trending — 3 sources updated this weekExploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 93%CVSS: 9.8Exploit: cisa kev · ssvc active · Metasploit · Exploit-DB (verified) · epss top5pct · epss high · public exploitExposed: 0

A fix is available — apply it.

Apache Shiro before 1.2.5, when a cipher key has not been configured for the "remember me" feature, allows remote attackers to execute arbitrary code or bypass intended access restrictions via an unspecified request parameter.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Act)
EG Risk 99/100SSVC: Act

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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Fix now — active exploitation, automatable, high impact.
EPSS PROB
93%
EPSS %ILE
100%
KEV
⚠ Exploited

Published

June 7, 2016

Last Modified

June 17, 2026

Advisory Details (7)

Auto-updated Sep 16, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic
http://rhn.redhat.com/errata/RHSA-2016-2035.html
generic

Locked Out | Packet Storm

http://packetstormsecurity.com/files/157497/Apache-Shiro-1.2.4-Remote-Code-Execution.html
generic

Locked Out | Packet Storm

http://packetstormsecurity.com/files/137310/Apache-Shiro-1.2.4-Information-Disclosure.html
generic
https://lists.apache.org/thread.html/ef3a800c7d727a00e04b78e2f06c5cd8960f09ca28c9b69d94c3c4c4%40%3Cannouncements.aurora.apache.org%3E
generic🔴 Active Exploitation

CVE-2016-4437 - PSIRT.COM

http://www.securityfocus.com/bid/91024
generic

SecurityFocus

http://www.securityfocus.com/archive/1/538570/100/0/threaded
generic
http://rhn.redhat.com/errata/RHSA-2016-2036.html

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibshiro-java (1.2.4-1ubuntu0.1~esm1) @ xenial2026-09-19ubuntu
redhatpatch2016-10-06redhat
redhatpatch2016-10-06redhat

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
shiro—1.2.5-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
shiro—1.2.5-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
shiro—1.2.5-1—
Maven(1)
PackageVulnerable rangeFixed inDependents
org.apache.shiro:shiro-core1.0.0-incubating ... 1.2.4 (7 versions)1.2.5—

Weakness Classification(1)

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

All Vendor Advisories

(3)

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 44× in last 7d / 198× 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.

Showing the most recent 100 of 731 total refreshes for this CVE.

  1. 2026-09-19 07:08 UTCVendor advisory
  2. 2026-09-19 02:47 UTCVendor advisory
  3. 2026-09-18 22:27 UTCVendor advisory
  4. 2026-09-18 19:20 UTCCISA KEV update
  5. 2026-09-18 18:07 UTCVendor advisory
  6. 2026-09-18 14:15 UTCCISA KEV update
  7. 2026-09-18 13:42 UTCVendor advisory
  8. 2026-09-18 09:21 UTCVendor advisory
  9. 2026-09-18 05:01 UTCVendor advisory
  10. 2026-09-18 00:41 UTCVendor advisory
  11. 2026-09-17 20:21 UTCVendor advisory
  12. 2026-09-17 16:01 UTCVendor advisory
  13. 2026-09-17 11:41 UTCVendor advisory
  14. 2026-09-17 07:20 UTCVendor advisory
  15. 2026-09-17 03:00 UTCVendor advisory
  16. 2026-09-16 22:40 UTCVendor advisory
  17. 2026-09-16 18:19 UTCEG score recompute
  18. 2026-09-16 18:19 UTCVendor advisory
  19. 2026-09-16 14:10 UTCCISA KEV update
  20. 2026-09-16 13:59 UTCVendor advisory
  21. 2026-09-16 09:39 UTCVendor advisory
  22. 2026-09-16 05:19 UTCVendor advisory
  23. 2026-09-16 00:59 UTCVendor advisory
  24. 2026-09-15 20:39 UTCVendor advisory
  25. 2026-09-15 16:19 UTCVendor advisory
Show 75 more
  1. 2026-09-15 11:59 UTCVendor advisory
  2. 2026-09-15 07:39 UTCVendor advisory
  3. 2026-09-15 03:19 UTCVendor advisory
  4. 2026-09-14 22:59 UTCVendor advisory
  5. 2026-09-14 19:24 UTCCISA KEV update
  6. 2026-09-14 18:39 UTCVendor advisory
  7. 2026-09-14 14:19 UTCVendor advisory
  8. 2026-09-14 09:59 UTCVendor advisory
  9. 2026-09-14 05:39 UTCVendor advisory
  10. 2026-09-14 01:19 UTCVendor advisory
  11. 2026-09-13 20:59 UTCVendor advisory
  12. 2026-09-13 16:38 UTCVendor advisory
  13. 2026-09-13 12:19 UTCVendor advisory
  14. 2026-09-13 07:59 UTCVendor advisory
  15. 2026-09-13 03:39 UTCVendor advisory
  16. 2026-09-12 23:19 UTCVendor advisory
  17. 2026-09-12 18:59 UTCVendor advisory
  18. 2026-09-12 14:39 UTCVendor advisory
  19. 2026-09-12 10:19 UTCVendor advisory
  20. 2026-09-12 05:59 UTCVendor advisory
  21. 2026-09-12 01:39 UTCVendor advisory
  22. 2026-09-11 21:19 UTCVendor advisory
  23. 2026-09-11 18:49 UTCCISA KEV update
  24. 2026-09-11 16:58 UTCVendor advisory
  25. 2026-09-11 12:37 UTCEG score recompute
  26. 2026-09-11 12:37 UTCVendor advisory
  27. 2026-09-11 08:16 UTCVendor advisory
  28. 2026-09-11 03:56 UTCVendor advisory
  29. 2026-09-10 23:36 UTCVendor advisory
  30. 2026-09-10 19:28 UTCCISA KEV update
  31. 2026-09-10 19:16 UTCVendor advisory
  32. 2026-09-10 14:56 UTCVendor advisory
  33. 2026-09-10 10:36 UTCEG score recompute
  34. 2026-09-10 10:36 UTCVendor advisory
  35. 2026-09-10 09:26 UTCEPSS rescore
  36. 2026-09-10 06:14 UTCVendor advisory
  37. 2026-09-10 01:54 UTCVendor advisory
  38. 2026-09-09 21:34 UTCVendor advisory
  39. 2026-09-09 19:08 UTCCISA KEV update
  40. 2026-09-09 17:13 UTCVendor advisory
  41. 2026-09-09 12:53 UTCVendor advisory
  42. 2026-09-09 08:32 UTCVendor advisory
  43. 2026-09-09 04:11 UTCVendor advisory
  44. 2026-09-08 23:51 UTCEG score recompute
  45. 2026-09-08 23:51 UTCVendor advisory
  46. 2026-09-08 19:28 UTCVendor advisory
  47. 2026-09-08 18:54 UTCCISA KEV update
  48. 2026-09-08 15:07 UTCVendor advisory
  49. 2026-09-08 10:43 UTCVendor advisory
  50. 2026-09-08 06:23 UTCVendor advisory
  51. 2026-09-08 02:02 UTCVendor advisory
  52. 2026-09-07 21:41 UTCVendor advisory
  53. 2026-09-07 17:21 UTCVendor advisory
  54. 2026-09-07 13:01 UTCVendor advisory
  55. 2026-09-07 08:34 UTCVendor advisory
  56. 2026-09-07 04:13 UTCVendor advisory
  57. 2026-09-06 23:52 UTCVendor advisory
  58. 2026-09-06 19:29 UTCVendor advisory
  59. 2026-09-06 15:08 UTCEG score recompute
  60. 2026-09-06 15:08 UTCVendor advisory
  61. 2026-09-06 10:47 UTCVendor advisory
  62. 2026-09-06 06:27 UTCVendor advisory
  63. 2026-09-06 02:07 UTCVendor advisory
  64. 2026-09-05 21:44 UTCVendor advisory
  65. 2026-09-05 17:23 UTCEG score recompute
  66. 2026-09-05 17:23 UTCVendor advisory
  67. 2026-09-05 13:00 UTCVendor advisory
  68. 2026-09-05 08:41 UTCVendor advisory
  69. 2026-09-05 04:21 UTCVendor advisory
  70. 2026-09-05 00:00 UTCVendor advisory
  71. 2026-09-04 19:40 UTCVendor advisory
  72. 2026-09-04 17:38 UTCCISA KEV update
  73. 2026-09-04 15:19 UTCVendor advisory
  74. 2026-09-04 10:57 UTCVendor advisory
  75. 2026-09-04 06:34 UTCVendor advisory

Publicly available exploits

(6 references)

Working exploit code is in the public domain (1 Metasploit module) (3 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCpizza-power/CVE-2016-4437
    First seen Dec 22, 2023

    Python POC to Exploit CVE-2016-4437 Apache Shiro Deserialization Vulnerability Due to Hardcode Encryption Key

    Open source ↗
  • GitHub PoC4nth0ny1130/shisoserial
    First seen Dec 23, 2021

    一个针对shiro反序列化漏洞(CVE-2016-4437)的快速利用工具/A simple tool targeted at shiro framework attacks with ysoserial.

    Open source ↗
  • GitHub PoCbkfish/Awesome_shiro
    First seen May 27, 2020

    CVE-2016-4437-Shiro反序列化爆破模块和key,命令执行，反弹shell的脚本

    Open source ↗
  • Exploit-DBEDB-48410✓ verified
    First seen May 1, 2020

    Apache Shiro 1.2.4 - Cookie RememberME Deserial RCE (Metasploit)

    Open source ↗
  • Metasploitexploit/multi/http/shiro_rememberme_v124_deserialize✓ verified
    First seen Jun 7, 2016

    Apache Shiro v1.2.4 Cookie RememberME Deserial RCE

    Open source ↗
  • Nucleihttp/cves/2016/CVE-2016-4437.yaml
    First seen Jan 1, 2016

    Apache Shiro 1.2.4 Cookie RememberME - Deserial Remote Code Execution Vulnerability

    Open source ↗

Frequently asked(6)

What is CVE-2016-4437?
CVE-2016-4437 is a critical vulnerability published on June 7, 2016. Apache Shiro before 1.2.5, when a cipher key has not been configured for the "remember me" feature, allows remote attackers to execute arbitrary code or bypass intended access restrictions via an unspecified request parameter.
When was CVE-2016-4437 disclosed?
CVE-2016-4437 was first published in the National Vulnerability Database on June 7, 2016, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-4437 actively exploited?
Yes. CISA added CVE-2016-4437 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Apache Shiro. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2016-4437?
CVE-2016-4437 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2016-4437?
CVE-2016-4437 affects Apache Shiro. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2016-4437?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-4437, 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-2016-4437

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