CyberSecBulletin
CVE-2026-53871NVD status: Deferred

hermes-webui: Reliance on Cookies without Validation and Integrity Checking

CVE-2026-53871 is a high-severity reliance on cookies without validation and integrity checking vulnerability in hermes-webui from Nesquena, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 0.51.368 as the first without the flaw, so updating hermes-webui to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update hermes-webui to 0.51.368 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
Nesquenahermes-webuibefore 0.51.3680.51.368

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (vulncheck.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.6HighCNA (vulncheck.com)
CVSS 3.18.1HighCNA (vulncheck.com)

Official description

Hermes WebUI before 0.51.368 contains an authorization bypass vulnerability in the get_profile_cookie() function that accepts unauthenticated profile names from the hermes_profile cookie. An authenticated attacker can forge the hermes_profile cookie value to bypass profile-scoped authorization checks and access sessions, files, and resources across different profiles.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Reliance on Cookies without Validation and Integrity Checking

The product relies on the existence or values of cookies when performing security-critical operations, but it does not properly ensure that the setting is valid for the associated user.

How developers prevent this class of flaw

  • Avoid using cookie data for a security-related decision.
  • Perform thorough input validation (i.e.: server side validation) on the cookie data if you're going to use it for a security related decision.
  • Add integrity checks to detect tampering.

More Reliance on Cookies without Validation and Integrity Checking vulnerabilities (CWE-565)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in hermes-webui

All hermes-webui vulnerabilities

Recent Reliance on Cookies without Validation and Integrity Checking vulnerabilities

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