CVE-2026-76834

HIGHPre-NVD 8.18.1
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 8.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-17. A secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-81681 (ENISA EUVD) · GHSA-2vrr-cgr4-gfmm (GitHub Security Advisories)Source: ENISA EUVD

8.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.8%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

b2evolution CMS versions 6.7.8 through 7.2.5 contain an incomplete fix for CVE-2016-8901 where the serialized-array object check in param_check_serialized_array() fails to reject payloads with negative integer array keys. Unauthenticated attackers can submit crafted serialized PHP objects via POST requests to htsrv/call_plugin.php that bypass validation and reach unserialize(), instantiating arbitrary PHP objects with attacker-chosen properties that may enable code execution if suitable POP gadget chains exist.

CVSS v3
8.1
EG Score
8.1HIGHmedium confidence
EG Risk
37
EG Risk 37/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity81% × 45%
Impact severity (EG Severity): CVSS 8.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.9% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.8%
EPSS %ILE
58th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.1): severity, escalated by confirmed exploitation. This CVE's 8.1 is its impact severity (EG Severity), not escalated.

EG Severity
8.1 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-05). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 17, 2026

Last Modified

September 23, 2026

Advisory Details (8)

Auto-updated Sep 17, 2026
Patch available. Sources: github_commit.
Web page

b2evolution CMS 6.7.8 through 7.2.5 Object Injection via Negative Integer Array Key | Advisories | VulnCheck

https://www.vulncheck.com/advisories/b2evolution-cms-6.7.8-through-7.2.5-object-injection-via-negative-integer-array-key
Web page

GitHub - b2evolution/b2evolution: b2evolution CMS: Multiblog/CMS content publishing + forums + email marketing + social network + more... b2evolution includes everything you need to run and maintain a modern website. Optimized for low maintenance with easy upgrades and effective antispam. Full RWD & bootstrap support. · GitHub

https://github.com/b2evolution/b2evolution
GitHub commit Patch Available

commit 335abf09bcea (b2evolution/b2evolution)

Patch available: b2evolution/b2evolution 6-9-4 (contains commit 335abf09bcea)

https://github.com/b2evolution/b2evolution/commit/335abf09bcea61717bd00bc1e3889f8100ebd1bb
GitHub commit Patch Available

commit 999b5ad1d597 (b2evolution/b2evolution)

Patch available: b2evolution/b2evolution 6-9-4 (contains commit 999b5ad1d597)

https://github.com/b2evolution/b2evolution/commit/999b5ad1d59760d7e450ceb541f55432fc74cd27
GitHub commit Patch Available

commit 25c21cf9cc42 (b2evolution/b2evolution)

Patch available: b2evolution/b2evolution 6-9-4 (contains commit 25c21cf9cc42)

https://github.com/b2evolution/b2evolution/commit/25c21cf9cc4261324001f9039509710b37ee2c4d
Web page

b2evolution/htsrv/call_plugin.php at 7.2.5 · b2evolution/b2evolution · GitHub

https://github.com/b2evolution/b2evolution/blob/7.2.5/htsrv/call_plugin.php#L49
Web page

b2evolution/inc/_core/_param.funcs.php at 7.2.5 · b2evolution/b2evolution · GitHub

https://github.com/b2evolution/b2evolution/blob/7.2.5/inc/_core/_param.funcs.php#L2860
Web page

CVE-2026-76834 — PHP Object Injection in b2evolution CMS (Incomplete Fix of CVE-2016-8901) · GitHub

https://gist.github.com/axg11/3e29501c33f6e1e05ac2a00107afd64e

Vendor Advisories for CVE-2026-76834(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 9× in last 7d / 56× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 139 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 39 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  2. 2026-11-05 20:55 UTCEG score recompute
  3. 2026-11-05 20:55 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  4. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  5. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  6. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  7. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  8. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  9. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  10. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  11. 2026-10-30 12:09 UTCEG score recompute
  12. 2026-10-30 12:09 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  13. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  14. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  15. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  16. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  17. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  18. 2026-10-25 14:01 UTCEG score recompute
  19. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  20. 2026-10-24 03:23 UTCEG score recompute
  21. 2026-10-24 03:23 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  22. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  23. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  24. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  25. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
Show 75 more
  1. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  2. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  3. 2026-10-18 03:12 UTCEG score recompute
  4. 2026-10-17 18:36 UTCEG score recompute
  5. 2026-10-17 18:36 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  6. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  7. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  8. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  9. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  10. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  11. 2026-10-13 07:03 UTCEG score recompute
  12. 2026-10-13 07:03 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  13. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  14. 2026-10-12 15:38 UTCEG score recompute
  15. 2026-10-12 05:01 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  16. 2026-10-11 19:23 UTCEG score recompute
  17. 2026-10-11 16:39 UTCEG score recompute
  18. 2026-10-11 14:01 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  19. 2026-10-11 13:58 UTCEG score recompute
  20. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  21. 2026-10-11 00:01 UTCEG score recompute
  22. 2026-10-11 00:01 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  23. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  24. 2026-10-10 11:08 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  25. 2026-10-09 22:15 UTCEG score recompute
  26. 2026-10-09 22:15 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  27. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  28. 2026-10-09 09:22 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  29. 2026-10-08 20:29 UTCEG score recompute
  30. 2026-10-08 20:29 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  31. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  32. 2026-10-08 07:01 UTCEG score recompute
  33. 2026-10-08 07:01 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  34. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  35. 2026-10-07 18:08 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  36. 2026-10-07 04:35 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  37. 2026-10-06 15:42 UTCEG score recompute
  38. 2026-10-06 15:42 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  39. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  40. 2026-10-06 02:27 UTCEG score recompute
  41. 2026-10-06 02:27 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  42. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  43. 2026-10-05 13:34 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  44. 2026-10-05 00:39 UTCEG score recompute
  45. 2026-10-05 00:39 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  46. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  47. 2026-10-04 11:45 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  48. 2026-10-03 22:53 UTCEG score recompute
  49. 2026-10-03 22:53 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  50. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  51. 2026-10-03 10:00 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  52. 2026-10-02 20:42 UTCEG score recompute
  53. 2026-10-02 20:42 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  54. 2026-10-02 07:49 UTCEG score recompute
  55. 2026-10-02 07:49 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  56. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  57. 2026-10-01 18:52 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  58. 2026-10-01 05:57 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  59. 2026-09-30 17:04 UTCEG score recompute
  60. 2026-09-30 17:04 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  61. 2026-09-30 04:11 UTCEG score recompute
  62. 2026-09-30 04:11 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  63. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  64. 2026-09-29 15:15 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  65. 2026-09-29 02:23 UTCEG score recompute
  66. 2026-09-29 02:23 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  67. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  68. 2026-09-28 13:30 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  69. 2026-09-28 00:36 UTCEG score recompute
  70. 2026-09-28 00:36 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  71. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  72. 2026-09-27 11:43 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  73. 2026-09-26 22:41 UTCEG score recompute
  74. 2026-09-26 22:41 UTCGHSA enrichmentGHSA-2vrr-cgr4-gfmm · GitHub severity CRITICAL · GitHub CVSS 8.1
  75. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.8% · 56th percentile

Frequently asked(5)

What is CVE-2026-76834?
CVE-2026-76834 is a high-severity vulnerability; its CVE record was published on September 17, 2026. b2evolution CMS versions 6.7.8 through 7.2.5 contain an incomplete fix for CVE-2016-8901 where the serialized-array object check in param_check_serialized_array() fails to reject payloads with negative integer array keys. Unauthenticated attackers can submit crafted serialized PHP objects via POST…
When was CVE-2026-76834 made public?
CVE-2026-76834 was made public on July 31, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on September 17, 2026. EchelonGraph's copy of the record carries a last-modified date of September 23, 2026; the record at its source may have been updated since.
Is CVE-2026-76834 actively exploited?
CVE-2026-76834 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.8% probability of exploitation in the next 30 days (58th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-76834?
CVE-2026-76834 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-76834?
A fix for CVE-2026-76834 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-76834 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-76834

Explore →

Is Your Infrastructure Affected by CVE-2026-76834?

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