Microsoft
Microsoft Authentication Library (MSAL) for Node.js Information Disclosure Vulnerability
At a glance
Low rather than Medium: UK relevance is 40 of 100, little UK-specific signal so far.
Briefing
- Do not treat uncorroborated claims as confirmed breaches.
Questions to ask IT
- Do we run Node.js, and which versions?
- If it is not yet patched, what mitigation is in place, and will the fix be done by 1 Dec?
Next steps
- Confirm whether this affects systems or suppliers in your estate
Vulnerability facts
Full CVE detail CVE-2026-109461- 5.9 · MediumExploitable over the network without any account, under specific conditions, and no one has to click or open anything. High impact on confidentiality.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- Not listed
- ~0.4% estimated chance of attack in 30 days
- Not linked from the CVE record
No technical write-up beyond these facts and the summary below yet.
Next steps
- Review the advisory against your asset inventory and patch cadence
Summary
- Origin validation error in Microsoft Authentication Library (MSAL) for Node.js allows an unauthorised attacker to disclose information over a network.
Read the original reportMicrosoft Security Update Guide RSS(opens in a new tab)
Products and services involved
- Node.js93% match confidence · CVE-2026-109461
Pulse
Last checked 1 Nov · Recheck overdue since 2 Nov 2026, 00:06 UK time · 1 quiet check collapsed
- Story15 Oct 2026, 22:44 UK time · 15 Oct
Linked reporting from Microsoft Security Update Guide RSS (vendor psirt).
Read source (Microsoft Security Update Guide RSS) - Signal1 Nov 2026, 00:06 UK time · 1 Nov
in the next 30 days first recorded at 0.4% (lower likelihood signal, not confirmed exploitation).
2 entries so far. The timeline chart appears once this story has more history.
Sources
CVE-2026-109461 Microsoft Authentication Library (MSAL) for Node.js Information Disclosure Vulnerability
How we know
Statements extracted from sources. Higher confidence means stronger corroboration.
- ClaimedHeadline60% confidence
Microsoft Authentication Library (MSAL) for Node.js Information Disclosure Vulnerability
- ProbableSummary fact75% confidence
Origin validation error in Microsoft Authentication Library (MSAL) for Node.js allows an unauthorised attacker to disclose information over a network.
- ConfirmedCVE identifier95% confidence
Event involves CVE-2026-109461