undici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens
CVSS score
5.9
EPSS probability
%0.3
Risk score
0.0
Published
4 d ago
Kanıt listesindeki ürün ve sürüm eşleşmesini kontrol edin; bazı varyantlar hâlâ etkileniyor olabilir.
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Vulnerability description
CVE AI research
DayBreach AI Explanation
Verified against sourcesSources read
2
Source agreement
Tam uyum
Evidence confidence
%63
Short explanation
A security vulnerability exists in undici, an HTTP client library for Node.js, where uppercase or mixed-case algorithm tokens in Subresource Integrity metadata are unrecognized, leading to the bypass of integrity checks.
This flaw impacts response integrity, allowing attackers to deliver mismatched response bodies to an application.
What should be done?
- Upgrade undici to versions 7.30.1 or 8.12.2
- Use lowercase algorithm tokens such as sha256, sha384, or sha512 in integrity metadata
Chain of evidence and sources
undici kütüphanesinin fetch() uygulaması, Subresource Integrity meta verilerini yalnızca küçük harfli bir kümeyle eşleştirerek doğrular.
Sürüm aralıkları 7.15.0 ile 7.30.0 ve 8.0.0 ile 8.12.1 arasında bu açıktan etkilenmektedir.
Show the technical text from the sources
undici is an HTTP client library for Node.js. In versions 7.15.0 through 7.30.0 and 8.0.0 through 8.12.1, its fetch() implementation verifies Subresource Integrity metadata by matching the algorithm token against a lowercase-only set, even though the SRI specification defines the token by its ASCII-lowercase form, so a valid but non-lowercase token such as an uppercase or mixed-case SHA256 is treated as unknown and skipped. When no recognized algorithm remains, undici treats the integrity list as empty and accepts the response, so a server returning a body that does not match the pinned digest passes the check. An attacker who controls only the response body can therefore deliver attacker-controlled bytes to an application that pinned a valid uppercase or mixed-case SRI token, with no integrity error, affecting response integrity only. The issue is fixed in undici 7.30.1 and 8.12.2, which normalize the algorithm token to ASCII lowercase before validation, and users should upgrade to one of those versions or later. As a workaround, use lowercase algorithm tokens such as sha256, sha384, or sha512 in integrity metadata.
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE: CWE-178
Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-109841 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 7.5 | CVSS V31 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | NVD |
| 5.9 | CVSS V3_1 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | CVE CNA |
| 5.9 | CVSS V31 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | NVD |
Patch and Remediation Guide
Solution & Remediation Advisory
1 düzeltme kanıtı bulundu; en az 3 ürün veya sürüm hâlâ etkileniyor ya da inceleniyor.
8.12.2+dfsg+~cs3.2.3-1Debian sid: 8.12.2+dfsg+~cs3.2.3-1
Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-109841 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-109841 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
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