{"id":"CVE-2026-76834","state":"PUBLISHED","title":"b2evolution CMS 6.7.8 through 7.2.5 Object Injection via Negative Integer Array Key","description":"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.","publishedAt":"2026-09-17T15:16:50.748Z","updatedAt":"2026-09-18T18:04:44.762Z","severity":{"score":9.2,"label":"Critical","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["b2evolution b2evolution CMS"],"affected":[{"vendor":"b2evolution","product":"b2evolution CMS","packageURL":"pkg:github/b2evolution/b2evolution","defaultStatus":"unaffected","versions":[{"version":"6.7.8","status":"affected","lessThanOrEqual":"7.2.5","versionType":"semver"}],"repo":"https://github.com/b2evolution/b2evolution"}],"references":["https://gist.github.com/axg11/3e29501c33f6e1e05ac2a00107afd64e","https://github.com/b2evolution/b2evolution/blob/7.2.5/inc/_core/_param.funcs.php#L2860","https://github.com/b2evolution/b2evolution/blob/7.2.5/htsrv/call_plugin.php#L49","https://github.com/b2evolution/b2evolution/commit/25c21cf9cc4261324001f9039509710b37ee2c4d","https://github.com/b2evolution/b2evolution/commit/999b5ad1d59760d7e450ceb541f55432fc74cd27","https://github.com/b2evolution/b2evolution/commit/335abf09bcea61717bd00bc1e3889f8100ebd1bb","https://b2evolution.net/news/2022/03/26/2022-update-eol","https://github.com/b2evolution/b2evolution","https://www.vulncheck.com/advisories/b2evolution-cms-6.7.8-through-7.2.5-object-injection-via-negative-integer-array-key"],"weaknesses":["CWE-502"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/76xxx/CVE-2026-76834.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-76834","state":"PUBLISHED","datePublished":"2026-09-17T15:16:50.748Z","dateUpdated":"2026-09-18T18:04:44.762Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-08-19T20:34:00.154Z"},"containers":{"cna":{"title":"b2evolution CMS 6.7.8 through 7.2.5 Object Injection via Negative Integer Array Key","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"b2evolution","product":"b2evolution CMS","packageURL":"pkg:github/b2evolution/b2evolution","defaultStatus":"unaffected","versions":[{"version":"6.7.8","status":"affected","lessThanOrEqual":"7.2.5","versionType":"semver"}],"repo":"https://github.com/b2evolution/b2evolution"}],"references":[{"url":"https://gist.github.com/axg11/3e29501c33f6e1e05ac2a00107afd64e","tags":["technical-description"]},{"url":"https://github.com/b2evolution/b2evolution/blob/7.2.5/inc/_core/_param.funcs.php#L2860","tags":["technical-description"]},{"url":"https://github.com/b2evolution/b2evolution/blob/7.2.5/htsrv/call_plugin.php#L49","tags":["technical-description"]},{"url":"https://github.com/b2evolution/b2evolution/commit/25c21cf9cc4261324001f9039509710b37ee2c4d","tags":["patch"],"name":"Incomplete fix for CVE-2016-8901 (1 of 2)"},{"url":"https://github.com/b2evolution/b2evolution/commit/999b5ad1d59760d7e450ceb541f55432fc74cd27","tags":["patch"],"name":"Incomplete fix for CVE-2016-8901 (2 of 2)"},{"url":"https://github.com/b2evolution/b2evolution/commit/335abf09bcea61717bd00bc1e3889f8100ebd1bb","tags":["technical-description","patch"],"name":"Introduces the flawed regular expression, first released in 6.7.8"},{"url":"https://b2evolution.net/news/2022/03/26/2022-update-eol","tags":["vendor-advisory"],"name":"b2evolution CMS end-of-life announcement"},{"url":"https://github.com/b2evolution/b2evolution","tags":["product"]},{"url":"https://www.vulncheck.com/advisories/b2evolution-cms-6.7.8-through-7.2.5-object-injection-via-negative-integer-array-key","name":"VulnCheck Advisory: b2evolution CMS 6.7.8 through 7.2.5 Object Injection via Negative Integer Array Key","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":9.2,"baseSeverity":"CRITICAL"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":8.1,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-502","lang":"en","description":"Deserialization of Untrusted Data","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-17T15:16:50.748Z"},"datePublic":"2026-07-31T00:00:00.000Z","tags":["unsupported-when-assigned"],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:b2evolution:b2evolution_cms:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7.8","versionEndIncluding":"7.2.5"}]}]}],"credits":[{"lang":"en","value":"Adrian Gaitan","type":"finder"},{"lang":"en","value":"VulnCheck","type":"coordinator"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-18T18:04:36.961014Z","id":"CVE-2026-76834","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-18T18:04:44.762Z"}}]}}}