CVE-2026-49406 json
Deno: BYONM module resolution allows `package.json` main path traversal to bypass `--allow-read` restrictions
published 2026-06-16 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-38545 , GHSA-968w-xfqw-vp9q , JLSEC-2026-657
- cvss
- 5.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.12, when Deno was run in BYONM mode (nodeModulesDir: "manual"), the module resolver did not validate that a package's resolved entrypoint stayed within its node_modules/<pkg>/ directory. A malicious package.json whose main field contained .. segments was able to resolve to an arbitrary path on disk, and the resolver then read that file without consulting the --allow-read allowlist. This let a require("evil-pkg") call return the contents of a file that a direct Deno.readTextFileSync(...) call would have been blocked from reading. This vulnerability is fixed in 2.7.12.
Patch / fix
- crates.io deno 2.7.12
- julia Deno_jll 2.8.1+0
- deno deno 2.7.12
- deno deno_runtime 2.7.12
- deno serde_v8 2.7.12
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| GitHub | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| OSV | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | deno | <2.7.12 |
2.7.12 |
| julia | Deno_jll | <2.8.1+0 |
2.8.1+0 |
Affected products
- denoland deno
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q
exploit, web, mitigation, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-49406
advisory
-
github.com
/denoland/deno
package
-
github.com
/advisories/GHSA-968w-xfqw-vp9q
web
Sources
- CVE List CVE-2026-49406
- GitHub Advisory GHSA-968w-xfqw-vp9q
- NVD CVE-2026-49406
- OSV JLSEC-2026-657
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.