CVE-2026-49356
Babel: Arbitrary File Read via sourceMappingURL Comment in @babel/core
Description
Babel is a compiler for writing next generation JavaScript. Prior to 8.0.0-rc.6 and 7.29.6, @babel/core affected by an arbitrary file read via a sourceMappingURL comment. Using @babel/core to compile maliciously crafted code can allow an attacker to read any source map from the system that is running Babel, if the attacker controls the input source code, can read the output source code, and knows the path of the source map file that they want to read. This vulnerability is fixed in 8.0.0-rc.6 and 7.29.6.
INFO
Published Date :
June 22, 2026, 6:16 p.m.
Last Modified :
June 26, 2026, 8:04 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | MITRE-CVE | ||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Update @babel/core to 8.0.0-rc.6 or 7.29.6.
- Ensure source map files are protected.
- Review input source code for malicious content.
Public PoC/Exploit Available at Github
CVE-2026-49356 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49356.
| URL | Resource |
|---|---|
| https://github.com/babel/babel/security/advisories/GHSA-4x5r-pxfx-6jf8 | Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49356 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-2026-49356
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Go Makefile Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-49356 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49356 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N Added CPE Configuration OR *cpe:2.3:a:babel:babel:8.0.0:alpha0:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha1:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha10:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha11:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha12:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha2:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha3:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha4:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha5:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha6:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha7:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha8:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha9:*:*:*:*:*:* *cpe:2.3:a:babel:babel:*:*:*:*:*:*:*:* versions up to (excluding) 7.29.6 *cpe:2.3:a:babel:babel:8.0.0:alpha13:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha14:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha15:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha16:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:alpha17:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:beta0:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:beta1:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:beta2:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:beta3:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:beta4:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:rc1:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:rc2:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:rc3:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:rc4:*:*:*:*:*:* *cpe:2.3:a:babel:babel:8.0.0:rc5:*:*:*:*:*:* Added Reference Type GitHub, Inc.: https://github.com/babel/babel/security/advisories/GHSA-4x5r-pxfx-6jf8 Types: Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 22, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-49356', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-22T17:22:57.466209Z'} -
New CVE Received by [email protected]
Jun. 22, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'babel', 'product': 'babel', 'versions': [{'status': 'affected', 'version': '>= 8.0.0-alpha.0, < 8.0.0-rc.5'}, {'status': 'affected', 'version': '< 7.29.6'}]}] Added Description Babel is a compiler for writing next generation JavaScript. Prior to 8.0.0-rc.6 and 7.29.6, @babel/core affected by an arbitrary file read via a sourceMappingURL comment. Using @babel/core to compile maliciously crafted code can allow an attacker to read any source map from the system that is running Babel, if the attacker controls the input source code, can read the output source code, and knows the path of the source map file that they want to read. This vulnerability is fixed in 8.0.0-rc.6 and 7.29.6. Added CVSS V3.1 AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N Added CWE CWE-22 Added CWE CWE-200 Added Reference https://github.com/babel/babel/security/advisories/GHSA-4x5r-pxfx-6jf8