CVE-2026-120423
undici vulnerable to Subresource Integrity bypass via whitespace in integrity metadata
undici is an HTTP client for Node.js. In versions 7.15.0 through 7.30.1 and 8.0.0 through 8.12.3, fetch verifies Subresource Integrity metadata by splitting the integrity string on a single space, but the SRI grammar separates metadata by ASCII whitespace, which also includes the horizontal tab. An integrity value whose digest is preceded by a tab or other ASCII whitespace is parsed as a single unrecognized token and skipped, and when no recognized algorithm remains undici treats the integrity list as empty and accepts the response, so a server returning a body different from the pinned digest passes the check. An application that pins a response with a valid but whitespace-surrounded SRI value receives attacker-controlled bytes with no integrity error, and the attacker needs only to control the response body, not the integrity metadata. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, supply SRI integrity metadata without surrounding whitespace, using a single space to separate multiple digests.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
undici vulnerable to Subresource Integrity bypass via whitespace in integrity metadata
undici is an HTTP client for Node.js. In versions 7.15.0 through 7.30.1 and 8.0.0 through 8.12.3, fetch verifies Subresource Integrity metadata by splitting the integrity string on a single space, but the SRI grammar separates metadata by ASCII whitespace, which also includes the horizontal tab. An integrity value whose digest is preceded by a tab or other ASCII whitespace is parsed as a single unrecognized token and skipped, and when no recognized algorithm remains undici treats the integrity list as empty and accepts the response, so a server returning a body different from the pinned digest passes the check. An application that pins a response with a valid but whitespace-surrounded SRI value receives attacker-controlled bytes with no integrity error, and the attacker needs only to control the response body, not the integrity metadata. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, supply SRI integrity metadata without surrounding whitespace, using a single space to separate multiple digests.
- Record
CVE-2026-120423- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-354
- Updated
- 2026-11-06
EUVDEUVD-2026-118182
undici is an HTTP client for Node.js. In versions 7.15.0 through 7.30.1 and 8.0.0 through 8.12.3, fetch verifies Subresource Integrity metadata by splitting the integrity string on a single space, but the SRI grammar separates metadata by ASCII whitespace, which also includes the horizontal tab. An integrity value whose digest is preceded by a tab or other ASCII whitespace is parsed as a single unrecognized token and skipped, and when no recognized algorithm remains undici treats the integrity list as empty and accepts the response, so a server returning a body different from the pinned digest passes the check. An application that pins a response with a valid but whitespace-surrounded SRI value receives attacker-controlled bytes with no integrity error, and the attacker needs only to control the response body, not the integrity metadata. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, supply SRI integrity metadata without surrounding whitespace, using a single space to separate multiple digests.
- Record
EUVD-2026-118182- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-06
NVD
undici is an HTTP client for Node.js. In versions 7.15.0 through 7.30.1 and 8.0.0 through 8.12.3, fetch verifies Subresource Integrity metadata by splitting the integrity string on a single space, but the SRI grammar separates metadata by ASCII whitespace, which also includes the horizontal tab. An integrity value whose digest is preceded by a tab or other ASCII whitespace is parsed as a single unrecognized token and skipped, and when no recognized algorithm remains undici treats the integrity list as empty and accepts the response, so a server returning a body different from the pinned digest passes the check. An application that pins a response with a valid but whitespace-surrounded SRI value receives attacker-controlled bytes with no integrity error, and the attacker needs only to control the response body, not the integrity metadata. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, supply SRI integrity metadata without surrounding whitespace, using a single space to separate multiple digests.
- Record
CVE-2026-120423- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-354
- Updated
- 2026-11-06
OSV
undici vulnerable to Subresource Integrity bypass via whitespace in integrity metadata
undici is an HTTP client for Node.js. In versions 7.15.0 through 7.30.1 and 8.0.0 through 8.12.3, fetch verifies Subresource Integrity metadata by splitting the integrity string on a single space, but the SRI grammar separates metadata by ASCII whitespace, which also includes the horizontal tab. An integrity value whose digest is preceded by a tab or other ASCII whitespace is parsed as a single unrecognized token and skipped, and when no recognized algorithm remains undici treats the integrity list as empty and accepts the response, so a server returning a body different from the pinned digest passes the check. An application that pins a response with a valid but whitespace-surrounded SRI value receives attacker-controlled bytes with no integrity error, and the attacker needs only to control the response body, not the integrity metadata. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, supply SRI integrity metadata without surrounding whitespace, using a single space to separate multiple digests.
- Record
CVE-2026-120423- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-354
- Updated
- 2026-11-07
OSVDEBIAN-CVE-2026-120423
undici is an HTTP client for Node.js. In versions 7.15.0 through 7.30.1 and 8.0.0 through 8.12.3, fetch verifies Subresource Integrity metadata by splitting the integrity string on a single space, but the SRI grammar separates metadata by ASCII whitespace, which also includes the horizontal tab. An integrity value whose digest is preceded by a tab or other ASCII whitespace is parsed as a single unrecognized token and skipped, and when no recognized algorithm remains undici treats the integrity list as empty and accepts the response, so a server returning a body different from the pinned digest passes the check. An application that pins a response with a valid but whitespace-surrounded SRI value receives attacker-controlled bytes with no integrity error, and the attacker needs only to control the response body, not the integrity metadata. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, supply SRI integrity metadata without surrounding whitespace, using a single space to separate multiple digests.
- Record
DEBIAN-CVE-2026-120423- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-07
OSVUBUNTU-CVE-2026-120423
undici is an HTTP client for Node.js. In versions 7.15.0 through 7.30.1 and 8.0.0 through 8.12.3, fetch verifies Subresource Integrity metadata by splitting the integrity string on a single space, but the SRI grammar separates metadata by ASCII whitespace, which also includes the horizontal tab. An integrity value whose digest is preceded by a tab or other ASCII whitespace is parsed as a single unrecognized token and skipped, and when no recognized algorithm remains undici treats the integrity list as empty and accepts the response, so a server returning a body different from the pinned digest passes the check. An application that pins a response with a valid but whitespace-surrounded SRI value receives attacker-controlled bytes with no integrity error, and the attacker needs only to control the response body, not the integrity metadata. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, supply SRI integrity metadata without surrounding whitespace, using a single space to separate multiple digests.
- Record
UBUNTU-CVE-2026-120423- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-07
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
node-undiciDebian:12 |
All versions, plus listed versions 5.15.0+dfsg1+~cs20.10.9.3-15.15.0+dfsg1+~cs20.10.9.3-1+deb12u15.15.0+dfsg1+~cs20.10.9.3-1+deb12u25.15.0+dfsg1+~cs20.10.9.3-1+deb12u35.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 Show 38 moreShow less5.19.1+dfsg1+~cs20.10.9.5-15.19.1+dfsg1+~cs20.10.9.5-25.22.1+dfsg1+~cs20.10.10.2-15.26.3+dfsg1+~cs23.10.12-15.26.3+dfsg1+~cs23.10.12-25.26.3+dfsg1+~cs23.10.12-35.28.0+dfsg1+~cs23.11.12.3-15.28.0+dfsg1+~cs23.11.12.3-25.28.2+dfsg1+~cs23.11.12.3-15.28.2+dfsg1+~cs23.11.12.3-25.28.2+dfsg1+~cs23.11.12.3-35.28.2+dfsg1+~cs23.11.12.3-45.28.2+dfsg1+~cs23.11.12.3-55.28.2+dfsg1+~cs23.11.12.3-65.28.4+dfsg1+~cs23.12.11-15.28.4+dfsg1+~cs23.12.11-27.1.0+dfsg1+~cs24.12.10-17.15.0+dfsg+~cs3.2.0-17.15.0+dfsg+~cs3.2.0-37.16.0+dfsg+~cs3.2.0-17.16.0+dfsg+~cs3.2.0-27.18.2+dfsg+~cs3.2.0-17.2.3+dfsg1+~cs24.12.11-17.2.3+dfsg1+~cs24.12.11-27.24.5+dfsg+~cs3.2.0-17.24.6+dfsg+~cs3.2.0-17.24.6+dfsg+~cs3.2.0-27.24.6+dfsg+~cs3.2.0-37.3.0+dfsg1+~cs24.12.11-17.3.0+dfsg1+~cs24.12.11-28.10.2+dfsg+~cs3.2.2-18.12.1+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-28.5.0+dfsg+~cs3.2.0-18.5.0+dfsg+~cs3.2.0-28.5.0+dfsg+~cs3.2.0-38.9.0+dfsg+~cs3.2.0-1 |
None known |
node-undiciDebian:13 |
All versions, plus listed versions 7.15.0+dfsg+~cs3.2.0-17.15.0+dfsg+~cs3.2.0-37.16.0+dfsg+~cs3.2.0-17.16.0+dfsg+~cs3.2.0-27.18.2+dfsg+~cs3.2.0-1 Show 14 moreShow less7.24.5+dfsg+~cs3.2.0-17.24.6+dfsg+~cs3.2.0-17.24.6+dfsg+~cs3.2.0-27.24.6+dfsg+~cs3.2.0-37.3.0+dfsg1+~cs24.12.11-17.3.0+dfsg1+~cs24.12.11-28.10.2+dfsg+~cs3.2.2-18.12.1+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-28.5.0+dfsg+~cs3.2.0-18.5.0+dfsg+~cs3.2.0-28.5.0+dfsg+~cs3.2.0-38.9.0+dfsg+~cs3.2.0-1 |
None known |
node-undiciDebian:14 |
All versions, plus listed versions 7.15.0+dfsg+~cs3.2.0-17.15.0+dfsg+~cs3.2.0-37.16.0+dfsg+~cs3.2.0-17.16.0+dfsg+~cs3.2.0-27.18.2+dfsg+~cs3.2.0-1 Show 14 moreShow less7.24.5+dfsg+~cs3.2.0-17.24.6+dfsg+~cs3.2.0-17.24.6+dfsg+~cs3.2.0-27.24.6+dfsg+~cs3.2.0-37.3.0+dfsg1+~cs24.12.11-17.3.0+dfsg1+~cs24.12.11-28.10.2+dfsg+~cs3.2.2-18.12.1+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-28.5.0+dfsg+~cs3.2.0-18.5.0+dfsg+~cs3.2.0-28.5.0+dfsg+~cs3.2.0-38.9.0+dfsg+~cs3.2.0-1 |
None known |
node-undiciUbuntu:24.04:LTS |
All versions, plus listed versions 5.22.1+dfsg1+~cs20.10.10.2-1ubuntu15.26.3+dfsg1+~cs23.10.12-2 |
None known |
node-undiciUbuntu:26.10 |
All versions, plus listed versions 7.18.2+dfsg+~cs3.2.0-1build17.24.6+dfsg+~cs3.2.0-38.5.0+dfsg+~cs3.2.0-28.5.0+dfsg+~cs3.2.0-38.9.0+dfsg+~cs3.2.0-1 |
None known |
node-undiciUbuntu:26.04:LTS |
All versions, plus listed versions 7.3.0+dfsg1+~cs24.12.11-27.16.0+dfsg+~cs3.2.0-27.18.2+dfsg+~cs3.2.0-17.18.2+dfsg+~cs3.2.0-1build1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| aliases, references | OSV | |
| affected, aliases, published, references | NVD, OSV | |
| cwes, severity, title | CVE List | |
| first indexed | EUVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-120423 is a medium vulnerability (CVSS 5.9) in Undici, published November 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.13%, the 2nd percentile. No source names a fixed version.
References
github.com/nodejs/undici/security/advisories/GHSA-r4pc-4jcp-7pqc
cna.openjsf.org/security-advisories.html
nvd.nist.gov/vuln/detail/CVE-2026-120423
security-tracker.debian.org/tracker/CVE-2026-120423
ubuntu.com/security/CVE-2026-120423
cve.org/CVERecord?id=CVE-2026-120423