CVE-2026-1528
ImpactA server can reply with a WebSocket frame using the 64-bit length form and an extremely large length. undici's ByteParser overflows internal math, ends up in an invalid state, and throws a fatal TypeError that terminates the process.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.50%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
ImpactA server can reply with a WebSocket frame using the 64-bit length form and an extremely large length. undici's ByteParser overflows internal math, ends up in an invalid state, and throws a fatal TypeError that terminates the process. Patches Patched in the undici version v7.24.0 and v6.24.0. Users should upgrade to this version or later.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.50% probability · 42th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-248, CWE-1284
- Affected
- nodejs/undici
- Source
- ce714d77-add3-4f53-aff5-83d477b104bb
EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://cna.openjsf.org/security-advisories.htmlVendor Advisory
- https://github.com/nodejs/undici/security/advisories/GHSA-f269-vfmq-vjvjVendor Advisory
- https://hackerone.com/reports/3537648Permissions Required
- https://access.redhat.com/errata/RHSA-2026:13826
- https://access.redhat.com/errata/RHSA-2026:17789
- https://access.redhat.com/errata/RHSA-2026:21772
- https://access.redhat.com/errata/RHSA-2026:21931
- https://access.redhat.com/errata/RHSA-2026:34342
- https://access.redhat.com/errata/RHSA-2026:5807
- https://access.redhat.com/errata/RHSA-2026:7080
- https://access.redhat.com/errata/RHSA-2026:7123
- https://access.redhat.com/errata/RHSA-2026:7302
- https://access.redhat.com/errata/RHSA-2026:7310
- https://access.redhat.com/errata/RHSA-2026:7350
- https://access.redhat.com/errata/RHSA-2026:7670
- https://access.redhat.com/errata/RHSA-2026:7675
- https://access.redhat.com/errata/RHSA-2026:7983
- https://access.redhat.com/errata/RHSA-2026:9742
- https://access.redhat.com/security/cve/CVE-2026-1528
- https://bugzilla.redhat.com/show_bug.cgi?id=2447145
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1528.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.