CVE-2026-1526

Highest-risk unexploited with PoCs

Exploit code exists, no confirmed in-the-wild activity, ranked by EPSS

Actively Exploited

Confirmed exploited in the wild, sorted by most recently updated

CVSS 7.5EPSS 1%

Published 2026-03-12Updated 2026-03-12

Vulnerability details

The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a "decompression bomb") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive. The vulnerability exists in the PerMessageDeflate.decompress() method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.

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

CNAopenjs

EPSS score history

Sources

3 links

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CVE Organization RedHat Vuln DB NVD Analysis

Profile

CVSS

7.5

EPSS

Published

2026-03-12

Updated

2026-03-12

CNA

openjs

Vendors

undici

1 product

CPEs

cpe:/a:redhat:cryostat:4::el9

cpe:/o:redhat:enterprise_linux_eus:10.0

cpe:/o:redhat:enterprise_linux:10.1

cpe:/a:redhat:enterprise_linux:8::appstream

cpe:/a:redhat:rhel_eus:9.6::appstream

cpe:/a:redhat:enterprise_linux:9::appstream

cpe:/a:redhat:rhdh:1.8::el9

cpe:/a:redhat:rhdh:1.9::el9

cpe:/a:redhat:openshift_ai:2.16::el8

cpe:/a:redhat:openshift_devspaces:3.28::el9

cpe:/a:redhat:openshift_pipelines:1.20::el9

cpe:/a:redhat:openshift_lightspeed

cpe:/a:redhat:openshift_pipelines:1

cpe:/a:redhat:rhdh:1

cpe:/a:redhat:openshift_ai

cpe:/a:redhat:openshift_devspaces:3

cpe:/a:redhat:ansible_portal:2

cpe:/a:redhat:jboss_enterprise_application_platform:8

cpe:/a:redhat:jbosseapxp

cpe:/a:redhat:cluster_observability_operator:1.5::el9

cpe:/a:redhat:enterprise_linux:8

cpe:/a:redhat:enterprise_linux:9

cpe:/a:redhat:rhel_eus:9.6

cpe:/a:redhat:openshift_data_foundation:4.18::el9

Vulnerability dashboard

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