Is CVE-2026-34939 in the CISA KEV catalog?

No. CVE-2026-34939 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-34939?

CVE-2026-34939 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2026-34939?

CVE-2026-34939 has an EPSS score of 0.40% (32th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-34939?

Upgrade praisonai to 4.5.90 or later.

CVE & CISA-KEV Catalog

CVE-2026-34939

MEDIUM

6.5

CVSS v3

NVD

Description

PraisonAI is a multi-agent teams system. Prior to version 4.5.90, MCPToolIndex.search_tools() compiles a caller-supplied string directly as a Python regular expression with no validation, sanitization, or timeout. A crafted regex causes catastrophic backtracking in the re engine, blocking the Python thread for hundreds of seconds and causing a complete service outage. This issue has been patched in version 4.5.90.

CWE-1333

How to fix

Remediation Available

praisonaiNVD

Affected:< 4.5.90Fixed in:4.5.90CVE-2026-34939derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

0.40%probability of exploitation in 30 days

32ndpercentile

Low risk: more likely to be exploited than 32% of all known CVEs.

References

Exploit1

github.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-09.