CVE-2026-55091

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• 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

0.49% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 42.3% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Received. NVD last modified this record on 2026-09-14.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

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

2026-09-14 17:26Z1 MO AGO

Last updated

2026-09-14 20:05Z1 MO AGO

Reserved

2026-06-16

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

High (CVSS 7.5)

CNA CVSS vector

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

Weaknesses

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

Data version

5.2

Document digest

d9de52b916cfd13a4420b9d335b8e9dd6a96f02b04c97ad42f66f22d755201ba

• github.comhttps://github.com/joaonuno/flat-to-nested-js/security/advisories/GHSA-hp36-v28f-w3r4x_refsource_CONFIRM
• github.comhttps://github.com/joaonuno/flat-to-nested-js/commit/680a5ebe1194edda16fa93baaa56ff14fe0e3d7fx_refsource_MISC
• github.comhttps://github.com/joaonuno/flat-to-nested-js/releases/tag/v1.1.2x_refsource_MISC