CVE-2026-19773

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 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

0.64% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 50.3% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-09-18.

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

2026-09-15 18:01Z1 MO AGO

Last updated

2026-09-16 03:57Z1 MO AGO

Reserved

2026-08-13

Assigning CNA

zdi

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-787Out-of-bounds WriteBase

Data version

5.2

Document digest

ae98ef58f5912df664ac1fa323ed794a4193f310a33863076cf0114fd014bcc5

• www.zerodayinitiative.comZDI-26-590https://www.zerodayinitiative.com/advisories/ZDI-26-590/x_research-advisory
• github.comvendor-provided URLhttps://github.com/warmcat/libwebsockets/commit/824151862f37bc72f46d9a3e01d5b9408d313a0bvendor-advisory