CVE-2026-12866

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.87% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 55.9% of scored records. A rank, not a probability.

NVD base score

9.2 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-07-07.

Red Hat severity

Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-06-23 05:00Z2 MO AGO

Last updated

2026-08-14 15:25Z20 DAYS AGO

Reserved

2026-06-22

Assigning CNA

snyk

Record state

PUBLISHED

Severity

Critical (CVSS 9.2)

CNA CVSS 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

Weaknesses

• CWE-94Improper Control of Generation of Code ('Code Injection')Base

Data version

5.2

Document digest

a1220016250cee39b898018a4aef527dc7126c8939b611985335c8dbf18eaca7

• security.snyk.iohttps://security.snyk.io/vuln/SNYK-JS-EXPREVAL-15054690
• security.snyk.iohttps://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-17662018
• github.comhttps://github.com/silentmatt/expr-eval/blob/master/src/expression.js%23L55
• github.comhttps://github.com/silentmatt/expr-eval/issues/292