CVE-2026-87930

HIGHPre-NVD 8.18.1—
EchelonGraph scoreHIGH confidence

Score 8.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-09. a secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: Elevated riskExposed: 0

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

MaxSite CMS through 109.6 passes the ci_session cookie to unserialize() without class restrictions, allowing unauthenticated attackers to inject PHP objects. Attackers can forge valid session cookies using the hardcoded encryption key to trigger magic methods and corrupt application state or achieve code execution if gadget classes exist.

CVSS v3
8.1
EG Score
8.1(high)
EG Risk
52(Track*)
EG Risk 52/100SSVC: 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
Severity81% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
27%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 9, 2026

Advisory Details (7)

Auto-updated Sep 9, 2026
No patch confirmed yet.
generic

MaxSite CMS through 109.6 PHP Object Injection via ci_session | Advisories | VulnCheck

https://www.vulncheck.com/advisories/maxsite-cms-through-109.6-php-object-injection-via-ci-session
generic

cms/application/config/config.php at 2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c · maxsite/cms · GitHub

https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/config/config.php#L230-L254
generic

maxsite-cve4/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.md at main · EviL0rd/maxsite-cve4 · GitHub

https://github.com/EviL0rd/maxsite-cve4/blob/main/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.md
generic

cms/system/libraries/Session.php at 2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c · maxsite/cms · GitHub

https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L740-L742
generic

cms/system/libraries/Session.php at 2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c · maxsite/cms · GitHub

https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L670-L680
generic

maxsite-cve6/2026.09.08-maxsite-cms-unsafe-unserialize-object-injection.md at main · EviL0rd/maxsite-cve6 · GitHub

https://github.com/EviL0rd/maxsite-cve6/blob/main/2026.09.08-maxsite-cms-unsafe-unserialize-object-injection.md
generic

GitHub - maxsite/cms: MaxSite CMS. Free CMS for your website. Smart alternative to WordPress · GitHub

https://github.com/maxsite/cms

Vendor Advisories for CVE-2026-87930(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 28× in last 7d / 50× 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. 2026-09-21 09:12 UTCGHSA enrichment
  2. 2026-09-20 21:41 UTCEG score recompute
  3. 2026-09-20 21:41 UTCGHSA enrichment
  4. 2026-09-20 20:16 UTCEPSS rescore
  5. 2026-09-20 10:10 UTCGHSA enrichment
  6. 2026-09-19 22:38 UTCEG score recompute
  7. 2026-09-19 22:38 UTCGHSA enrichment
  8. 2026-09-19 11:07 UTCGHSA enrichment
  9. 2026-09-18 23:36 UTCEG score recompute
  10. 2026-09-18 23:36 UTCGHSA enrichment
  11. 2026-09-18 19:28 UTCEPSS rescore
  12. 2026-09-18 12:03 UTCGHSA enrichment
  13. 2026-09-18 00:30 UTCEG score recompute
  14. 2026-09-18 00:30 UTCGHSA enrichment
  15. 2026-09-17 19:32 UTCEPSS rescore
  16. 2026-09-17 12:59 UTCGHSA enrichment
  17. 2026-09-17 01:25 UTCEG score recompute
  18. 2026-09-17 01:25 UTCGHSA enrichment
  19. 2026-09-16 14:09 UTCEPSS rescore
  20. 2026-09-16 13:54 UTCEG score recompute
  21. 2026-09-16 13:54 UTCGHSA enrichment
  22. 2026-09-16 05:15 UTCEPSS rescore
  23. 2026-09-16 02:22 UTCGHSA enrichment
  24. 2026-09-15 14:51 UTCGHSA enrichment
  25. 2026-09-15 03:19 UTCEG score recompute
Show 25 more
  1. 2026-09-15 03:19 UTCGHSA enrichment
  2. 2026-09-15 03:12 UTCEPSS rescore
  3. 2026-09-14 15:47 UTCGHSA enrichment
  4. 2026-09-14 04:15 UTCEG score recompute
  5. 2026-09-14 04:15 UTCGHSA enrichment
  6. 2026-09-13 16:48 UTCEPSS rescore
  7. 2026-09-13 16:44 UTCGHSA enrichment
  8. 2026-09-13 05:12 UTCGHSA enrichment
  9. 2026-09-12 17:41 UTCEG score recompute
  10. 2026-09-12 17:41 UTCGHSA enrichment
  11. 2026-09-12 15:02 UTCEPSS rescore
  12. 2026-09-12 06:09 UTCGHSA enrichment
  13. 2026-09-11 18:38 UTCEG score recompute
  14. 2026-09-11 18:38 UTCGHSA enrichment
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-11 14:53 UTCEPSS rescore
  17. 2026-09-11 07:06 UTCGHSA enrichment
  18. 2026-09-10 19:35 UTCGHSA enrichment
  19. 2026-09-10 08:04 UTCGHSA enrichment
  20. 2026-09-09 20:32 UTCEG score recompute
  21. 2026-09-09 20:32 UTCGHSA enrichment
  22. 2026-09-09 18:28 UTCEG score recompute
  23. 2026-09-09 17:28 UTCEG score recompute
  24. 2026-09-09 16:55 UTCEG score recompute
  25. 2026-09-09 16:54 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-87930?
CVE-2026-87930 is a high vulnerability published on September 9, 2026. MaxSite CMS through 109.6 passes the ci_session cookie to unserialize() without class restrictions, allowing unauthenticated attackers to inject PHP objects. Attackers can forge valid session cookies using the hardcoded encryption key to trigger magic methods and corrupt application state or…
When was CVE-2026-87930 disclosed?
CVE-2026-87930 was first published in the National Vulnerability Database on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87930 actively exploited?
CVE-2026-87930 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 72.8% of all scored CVEs.
What is the CVSS score of CVE-2026-87930?
CVE-2026-87930 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-87930?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87930, 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

Explore the affected products and dependency analysis for CVE-2026-87930

Explore →

Is Your Infrastructure Affected by CVE-2026-87930?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs