# CVE-2026-49356: Babel: Arbitrary File Read via sourceMappingURL Comment in @babel/core > Attackers can read arbitrary source map files from the system by crafting malicious input code processed by Babel, exposing sensitive source code. - **Severity:** Low 3.2 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 22 Jun 2026 - **Updated:** 22 Jun 2026 - **Also known as:** CLEANSTART-2026-SW35830, CLSA-2026-1784596301, CLSA-2026-1790109160, CLSA-2026-1790181820, CLSA-2026-1790212818, CLSA-2026-1792160971, CLSA-2026-1792160977, CLSA-2026-1792161421, CLSA-2026-1792161428, CLSA-2026-1792161619, CLSA-2026-1792161630, CLSA-2026-1792161633, CLSA-2026-1792161634, CLSA-2026-1792161669, CLSA-2026-1792161734, CLSA-2026-1792161742, CLSA-2026-1792161744, CLSA-2026-1792161746, CLSA-2026-1792161837, CLSA-2026-1792161889, CLSA-2026-1792161897, CLSA-2026-1792161899, CLSA-2026-1792161900, CLSA-2026-1792161960, CLSA-2026-1792161986, CLSA-2026-1792161993, CLSA-2026-1792162027, CLSA-2026-1792162052, CLSA-2026-1792162077, CLSA-2026-1792162092, CLSA-2026-1792162098, CLSA-2026-1792162116, CLSA-2026-1792162121, CLSA-2026-1792162140, CLSA-2026-1792162159, CLSA-2026-1792162165, CLSA-2026-1792162181, CLSA-2026-1792162187, CLSA-2026-1792162211, CLSA-2026-1792162220, CLSA-2026-1792162222, CLSA-2026-1792162223, CLSA-2026-1792163449, CLSA-2026-1792163452, CLSA-2026-1792163453, CLSA-2026-1792194431, CLSA-2026-1792194435, CLSA-2026-1792194451, CLSA-2026-1792201266, CLSA-2026-1792201269, CLSA-2026-1792232596, CLSA-2026-1792241959, CLSA-2026-1792278639, CLSA-2026-1792278642, CLSA-2026-1792278649, CLSA-2026-1792283510, CLSA-2026-1792283516, CLSA-2026-1792283520, CLSA-2026-1792285565, CLSA-2026-1792285568, CLSA-2026-1792285572, CLSA-2026-1792286713, CLSA-2026-1792286716, CLSA-2026-1792286720, CLSA-2026-1792289875, CLSA-2026-1792289877, CLSA-2026-1792291420, CLSA-2026-1792291424, CLSA-2026-1792291428, CLSA-2026-1792292301, CLSA-2026-1792292303, CLSA-2026-1792302624, CLSA-2026-1792302629, CLSA-2026-1792304212, CLSA-2026-1792304219, CLSA-2026-1792304224, CLSA-2026-1792304225, CLSA-2026-1792306784, CLSA-2026-1792308467, CLSA-2026-1792309335, CLSA-2026-1792312964, CLSA-2026-1792312967, CLSA-2026-1792342441, CLSA-2026-1792342444, CLSA-2026-1792342452, CLSA-2026-1792342454, CLSA-2026-1792361349, CLSA-2026-1792361352, CLSA-2026-1792361358, CLSA-2026-1792369492, CLSA-2026-1792369495, CLSA-2026-1792369504, CLSA-2026-1792369505, CLSA-2026-1792373913, CLSA-2026-1792373921, CLSA-2026-1792373922, CLSA-2026-1792373927, CLSA-2026-1792373929, CLSA-2026-1792378047, CLSA-2026-1792378050, CLSA-2026-1792378053, CLSA-2026-1792384640, CLSA-2026-1792384642, CLSA-2026-1792384644, CLSA-2026-1792388614, CLSA-2026-1792388618, CLSA-2026-1792388622, CLSA-2026-1792393378, CLSA-2026-1792393379, CLSA-2026-1792393383, CLSA-2026-1792411626, CLSA-2026-1792411629, CLSA-2026-1792411633, CLSA-2026-1792411638, CLSA-2026-1792418550, CLSA-2026-1792418554, CLSA-2026-1792418558, CLSA-2026-1792418562, CLSA-2026-1792421257, CLSA-2026-1792421266, CLSA-2026-1792421268, CLSA-2026-1792421269, CLSA-2026-1792421282, CLSA-2026-1792423753, CLSA-2026-1792423762, CLSA-2026-1792423763, CLSA-2026-1792423774, CLSA-2026-1792423780, CLSA-2026-1792426994, CLSA-2026-1792426999, CLSA-2026-1792427003, CLSA-2026-1792432139, CLSA-2026-1792432145, CLSA-2026-1792432149, CLSA-2026-1792435129, CLSA-2026-1792435132, CLSA-2026-1792435138, CLSA-2026-1792438115, CLSA-2026-1792438118, CLSA-2026-1792438119, CLSA-2026-1792438124, CLSA-2026-1792440912, CLSA-2026-1792440921, CLSA-2026-1792440930, CLSA-2026-1792444947, CLSA-2026-1792444949, CLSA-2026-1792444953, CLSA-2026-1792447093, CLSA-2026-1792447094, CLSA-2026-1792447100, CLSA-2026-1792447101, CLSA-2026-1792448758, CLSA-2026-1792448760, CLSA-2026-1792448763, CLSA-2026-1792452565, CLSA-2026-1792452569, CLSA-2026-1792452575, CLSA-2026-1792452576, CLSA-2026-1792452589, CLSA-2026-1792455074, CLSA-2026-1792455079, CLSA-2026-1792455085, CLSA-2026-1792455086, CLSA-2026-1792455100, CLSA-2026-1792457907, CLSA-2026-1792457912, CLSA-2026-1792457917, CLSA-2026-1792460541, CLSA-2026-1792460548, CLSA-2026-1792460551, CLSA-2026-1792461784, CLSA-2026-1792461787, CLSA-2026-1792486524, CLSA-2026-1792486527, CLSA-2026-1792486531, CLSA-2026-1792486532, CLSA-2026-1792489214, CLSA-2026-1792489218, CLSA-2026-1792494691, CLSA-2026-1792494695, CLSA-2026-1792494699, CLSA-2026-1792495996, CLSA-2026-1792495998, CLSA-2026-1792496003, CLSA-2026-1792496009, CLSA-2026-1792496620, CLSA-2026-1792496623, CLSA-2026-1792498116, CLSA-2026-1792498122, CLSA-2026-1792498127, CLSA-2026-1792498129, CLSA-2026-1792499601, CLSA-2026-1792499606, CLSA-2026-1792499610, CLSA-2026-1792500788, CLSA-2026-1792502891, CLSA-2026-1792502895, CLSA-2026-1792502900, CLSA-2026-1792504876, CLSA-2026-1792504881, CLSA-2026-1792504885, CLSA-2026-1792506471, CLSA-2026-1792506475, CLSA-2026-1792506480, CLSA-2026-1792508334, CLSA-2026-1792508338, CLSA-2026-1792508341, CLSA-2026-1792509040, CLSA-2026-1792510077, CLSA-2026-1792512824, CLSA-2026-1792512831, CLSA-2026-1792512834, CLSA-2026-1792514583, CLSA-2026-1792514587, CLSA-2026-1792514592, CLSA-2026-1792516117, CLSA-2026-1792516121, CLSA-2026-1792516124, CLSA-2026-1792517646, CLSA-2026-1792517653, CLSA-2026-1792517656, CLSA-2026-1792518697, CLSA-2026-1792518700, CLSA-2026-1792520490, CLSA-2026-1792520494, CLSA-2026-1792520498, CLSA-2026-1792522727, CLSA-2026-1792522738, CLSA-2026-1792522741, CLSA-2026-1792522742, CLSA-2026-1792525283, CLSA-2026-1792525286, CLSA-2026-1792525291, CLSA-2026-1792526961, CLSA-2026-1792526963, CLSA-2026-1792526971, CLSA-2026-1792529422, CLSA-2026-1792529425, CLSA-2026-1792529428, CLSA-2026-1792530395, CLSA-2026-1792530396, CLSA-2026-1792532442, CLSA-2026-1792532444, CLSA-2026-1792532447, CLSA-2026-1792536112, CLSA-2026-1792536117, CLSA-2026-1792537735, CLSA-2026-1792537740, CLSA-2026-1792537744, CLSA-2026-1792539096, CLSA-2026-1792539100, CLSA-2026-1792540672, CLSA-2026-1792540676, CLSA-2026-1792540680, CLSA-2026-1792542241, CLSA-2026-1792542247, CLSA-2026-1792542251, CLSA-2026-1792542253, CLSA-2026-1792543808, CLSA-2026-1792545143, CLSA-2026-1792545150, CLSA-2026-1792760090, CLSA-2026-1792760119, CLSA-2026-1792760135, CLSA-2026-1792868961, CLSA-2026-1792868974, CLSA-2026-1792868976, CLSA-2026-1793141357, CLSA-2026-1793141359, CLSA-2026-1793141360, CLSA-2026-1793141406, CLSA-2026-1793141409, CLSA-2026-1793141505, CLSA-2026-1793154864, CLSA-2026-1793154869, CLSA-2026-1793154887, CLSA-2026-1793154960, CLSA-2026-1793159554, CLSA-2026-1793159579, CLSA-2026-1793159586, CLSA-2026-1793162333, CLSA-2026-1793162368, CLSA-2026-1793162376, CLSA-2026-1793165567, CLSA-2026-1793165586, CLSA-2026-1793173354, CLSA-2026-1793173379, CLSA-2026-1793173387, CLSA-2026-1793173393, CLSA-2026-1793173420, CLSA-2026-1793175186, CLSA-2026-1793199716, CLSA-2026-1793199826, CLSA-2026-1793199937, CLSA-2026-1793200039, CLSA-2026-1793200196, CLSA-2026-1793200300, CLSA-2026-1793203012, DEBIAN-CVE-2026-49356, GHSA-4x5r-pxfx-6jf8, MINI-7gwm-83cr-w9rx, MINI-9gwp-43j3-g67v, MINI-9hh9-x38r-qhh4, MINI-cj8x-7pr2-69r5, MINI-hj58-qjwv-wcv3, MINI-j6v7-34jc-w38w, MINI-m88g-h355-2r45, MINI-mq2j-hv64-mc7v, MINI-pq7c-vc7r-fpr2, MINI-rhwg-mxwm-3hrq, MINI-rvvj-97wf-2wgv, MINI-v2h3-979v-m57v, MINI-vjjq-cmvh-268f, UBUNTU-CVE-2026-49356 ## What is CVE-2026-49356? CVE-2026-49356 is a low-severity path traversal vulnerability in babel, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official 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. Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) ## Which versions are affected by CVE-2026-49356? 4 open source packages ship an affected version, including @babel/core. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `@babel/core` | npm | All versions | 7.29.6 | | `@babel/core` | npm | All versions | 7.29.6 | | `@babel/core` | npm | From 8.0.0-alpha.0 | 8.0.0-rc.6 | | `@babel/core` | npm | From 8.0.0-alpha.0 | 8.0.0-rc.6 | Products: Babel Babel. ## How do I fix CVE-2026-49356? Upgrade @babel/core to a fixed version for your release line: 7.29.6 or 8.0.0-rc.6. ## Is CVE-2026-49356 being exploited? There is no known exploitation of CVE-2026-49356 in the wild and no public exploit code. ## Other vulnerabilities in babel - [CVE-2026-44728](https://insights.sbomify.com/CVE-2026-44728/): @babel/plugin-transform-modules-systemjs generates arbitrary code when compiling malicious input (high 8.2) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-49356 and fix it if it is affected. What it is: CVE-2026-49356 is a low-severity path traversal vulnerability in babel, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-49356 in the wild and no public exploit code. Affected packages and fixed versions: - @babel/core (npm): affected all versions; fixed in 7.29.6 - @babel/core (npm): affected all versions; fixed in 7.29.6 - @babel/core (npm): affected from 8.0.0-alpha.0; fixed in 8.0.0-rc.6 - @babel/core (npm): affected from 8.0.0-alpha.0; fixed in 8.0.0-rc.6 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-49356/ (Markdown: https://insights.sbomify.com/CVE-2026-49356/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49356 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49356 - OSV: https://osv.dev/vulnerability/CVE-2026-49356 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-49356/ Summaries are generated and may contain mistakes; the official description above is the record.