CVE-2011-10018

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2025-08-13. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Weaponized
9.8EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • Public exploit code is available (Metasploit, ssvc poc, public exploit)
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 9.8Exploit: Metasploit · ssvc poc · public exploitExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

myBB version 1.6.4 was distributed with an unauthorized backdoor embedded in the source code. The backdoor allowed remote attackers to execute arbitrary PHP code by injecting payloads into a specially crafted collapsed cookie. This vulnerability was introduced during packaging and was not part of the intended application logic. Exploitation requires no authentication and results in full compromise of the web server under the context of the web application.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
85(Attend)
EG Risk 85/100SSVC: Attend

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%
Exploitation65% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
2%
EPSS %ILE
78%
KEV
Not listed

Published

August 13, 2025

Last Modified

August 14, 2025

Advisory Details (4)

Auto-updated Jun 6, 2026
No patch confirmed yet.
generic
https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/unix/webapp/mybb_backdoor.rb
generic

myBB 1.6.4 Backdoor Arbitrary Command Execution | Advisories | VulnCheck

https://www.vulncheck.com/advisories/mybb-backdoor-arbitrary-command-execution
generic

MyBB Compromised Source Packages Backdoor Security Issue - Secunia.com

https://web.archive.org/web/20111015224948/http://secunia.com/advisories/46300/
generic

1.6.4 Security Vulnerability | MyBB Blog

https://blog.mybb.com/2011/10/06/1-6-4-security-vulnerabilit/

Weakness Classification(2)

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

Data Freshness Timeline

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

Publicly available exploits

(1 reference)

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

  • Metasploitexploit/unix/webapp/mybb_backdoor✓ verified
    First seen Oct 6, 2011

    myBB 1.6.4 Backdoor Arbitrary Command Execution

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2011-10018?
CVE-2011-10018 is a critical vulnerability published on August 13, 2025. myBB version 1.6.4 was distributed with an unauthorized backdoor embedded in the source code. The backdoor allowed remote attackers to execute arbitrary PHP code by injecting payloads into a specially crafted collapsed cookie. This vulnerability was introduced during packaging and was not part of…
When was CVE-2011-10018 disclosed?
CVE-2011-10018 was first published in the National Vulnerability Database on August 13, 2025, with the most recent update on August 14, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2011-10018 actively exploited?
CVE-2011-10018 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 21.6% of all scored CVEs.
What is the CVSS score of CVE-2011-10018?
CVE-2011-10018 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2011-10018?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2011-10018, 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

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