CVE-2026-49356: Babel: Arbitrary File Read via sourceMappingURL Comment in @babel/core

lowCVSS 3.2CVE-2026-49356

CSIRTS triage

vendor: Babel product: Babel Information disclosure

What: An arbitrary file read can occur via sourceMappingURL comments.
Who is affected: Users of Babel that utilize sourceMappingURL.
Urgency: Remediation is low urgency due to a low severity rating of 3.2.
Action: Consider updating Babel to mitigate the risk.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: low — CVSS 3.2
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-49356

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-493560.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-49356	coverage & exploitation status	NVD · CVE.org

Recent advisories for Babel

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highGHSA-55f6-pf8r-c2f4: Open Babel has out-of-bounds write in MOPAC translationVectors[] (UNIT CELL TRANSLATION)ghsa · 2026-07-06