CVE-2026-90771

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.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited 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

0.38% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 32.7% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/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

Awaiting Analysis. NVD last modified this record on 2026-09-24.

Red Hat severity

Moderate. 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

2026-09-13 10:45Z1 MO AGO

Last updated

2026-09-24 14:21Z1 MO AGO

Reserved

2026-09-13

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Medium (CVSS 6.3)

CNA CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Weaknesses

• CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')Variant
• CWE-915Improperly Controlled Modification of Dynamically-Determined Object AttributesBase

Data version

5.2

Document digest

ea022c74829d67f1c54b58a45a214b03eaedb52d9c31f637a111370e1cddc9d7

• github.comGitHub Issue #3150https://github.com/hapijs/joi/issues/3150issue-tracking
• github.comhttps://github.com/hapijs/joiproduct
• github.comhttps://github.com/hapijs/joi/blob/v18.2.8/lib/messages.jstechnical-description
• github.comhttps://github.com/hapijs/joi/commit/5b8333c9177e08b4ef4ed02903c2d657084e7afbpatch
• www.vulncheck.comVulnCheck Advisory: joi before 17.13.8 and 18.2.9 Prototype Pollution via messageshttps://www.vulncheck.com/advisories/joi-before-17.13.8-and-18.2.9-prototype-pollution-via-messagesthird-party-advisory