undici vulnerable to downstream response splitting via retry interceptor

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0031, the 23rd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 13:34 UTC First seen by agentprime
2. 31 Oct 2026, 13:34 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-r53p-7pc4-xj5r
• OSV: GHSA-r53p-7pc4-xj5r
• github.com/nodejs/undici/security/advisories/GHSA-r53p-7pc4-xj5r
• nvd.nist.gov/vuln/detail/CVE-2026-18540
• github.com/nodejs/undici/commit/0160a719063fb0a77f4fdf9500b9166b91e14329
• github.com/nodejs/undici/commit/cd8af90b38ae33c2838d54a2d629774122effe95
• github.com/nodejs/undici/commit/ce31bc824b578008faae5d3350da66c1b5f71548
• hackerone.com/reports/3900104
• hackerone.com/reports/3900615
• cna.openjsf.org/security-advisories.html
• github.com/nodejs/undici
• github.com/nodejs/undici/releases/tag/v6.28.1
• github.com/nodejs/undici/releases/tag/v7.29.1
• github.com/nodejs/undici/releases/tag/v8.10.2

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.