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Fencer Vulns
medium 6.5

CVE-2026-55369 json

Waline login accepts a non-string email as a match-all MongoDB query

published 2026-10-28 11 d ago modified 2026-11-02 6 d ago also GHSA-jf75-q64q-g65r , EUVD-2026-112060

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

Waline is a comment system with backend support. Prior to version 1.41.1, the login endpoint POST /api/token reads the email field from the request body without checking its type and passes it straight into the MongoDB storage query. When email is not a string (for example a JSON object such as {"$ne": null}), the MongoDB storage adapter's parseWhere silently DROPS the field rather than rejecting the request, producing an empty filter that matches ALL users. The endpoint then verifies the submitted password against the FIRST user returned (user[0]), which in Waline is the first-registered user — the site administrator. This is a PARTIAL authentication bypass, not a full one. The attacker still needs a valid password for that first user; this is not a zero-knowledge bypass and it does not disclose passwords. Its concrete effects are: (1) the email/identifier factor is removed for the administrator account, (2) user enumeration (a non-string email never fails the "no such user" branch), and (3) credential-stuffing amplification — an attacker can test a leaked or weak password against the administrator account without knowing the administrator's email. This issue has been patched in version 1.41.1.

Patch / fix

  • npm @waline/vercel 1.41.0

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
6 d ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/walinejs/waline/security/advisories/GHSA-jf75-q64q-g65r referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm @waline/vercel
<1.41.0
1.41.0

Affected products

  • walinejs waline

Classification

Weakness
  • CWE-287 Improper Authentication
  • CWE-943 Improper Neutralization of Special Elements in Data Query Logic

References

Sources

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.