CVE-2026-39888: Praison Praisonai vulnerability (CVSS 9.9)

Description

PraisonAI is a multi-agent teams system. Prior to 1.5.115, execute_code() in praisonaiagents.tools.python_tools defaults to sandbox_mode="sandbox", which runs user code in a subprocess wrapped with a restricted __builtins__ dict and an AST-based blocklist. The AST blocklist embedded inside the subprocess wrapper (blocked_attrs of python_tools.py) contains only 11 attribute names — a strict subset of the 30+ names blocked in the direct-execution path. The four attributes that form a frame-traversal chain out of the sandbox are all absent from the subprocess list (__traceback__, tb_frame, f_back, and f_builtins). Chaining these attributes through a caught exception exposes the real Python builtins dict of the subprocess wrapper frame, from which exec can be retrieved and called under a non-blocked variable name — bypassing every remaining security layer. This vulnerability is fixed in 1.5.115.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredLow

User interactionNone

ScopeChanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

Praison Praisonai< 1.5.115

Remediation

Fixed in

Praison Praisonai≥ 1.5.115

Patch & vendor advisories

https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-qf73-2hrx-xprp

References

https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-qf73-2hrx-xprpVendor Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-39888 being actively exploited?

CVE-2026-39888 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.61%.

How severe is CVE-2026-39888?

CVE-2026-39888 has a CVSS 3.1 base score of 9.9, rated critical. EPSS estimates a 0.61% probability of exploitation.

Which products are affected by CVE-2026-39888?

Affected products include Praison Praisonai.

How do I fix CVE-2026-39888?

Upgrade affected software to a fixed version, for example Praison Praisonai 1.5.115 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-39888 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation works Book a demo