by Kastro
Paper/Archive/CVE-2026-55536

CVE-2026-55536

MervinPraison PraisonAI — Browser Server WebSocket origin validation bypass via unanchored regex (patch bypass of CVE-2026-40289 / GHSA-8x8f-54wf-vv92)

EPSS 0.5%public exploitCVSS 9.1
critical.is priorityof 100
46
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 44.2.442 × 208.8Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, Browser Server _handle_connection() checks Chrome extension origins with re.match() and the unanchored expression chrome-extension://[a-z0-9]{32}. Extra trailing characters pass before websocket.accept(), allowing start_session commands and unauthorized browser automation. This issue is fixed in version 4.6.58.

Affected

ProductAffectedFixed inSource
PraisonAI< 4.6.58–CNA

Scores by source

GitHub_M (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/MervinPraison/PraisonAI/security/advisories/GHSA-6g6r-q6gw-w8fgrefgithub.com/MervinPraison/PraisonAI/commit/2f9677abb2ea68eab864ee8b6a828fd0141612e1refgithub.com/MervinPraison/PraisonAI/releases/tag/v4.6.58