CyberSecBulletin
CVE-2026-63462NVD status: Deferred

unleash: Uncontrolled Recursion

Published Updated By the CyberSecBulletin desk

CVE-2026-63462 is a high-severity uncontrolled recursion vulnerability in unleash, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected unleash versions: < 7.5.2; >= 7.6.0, < 7.6.5; >= 8.0.0, < 8.0.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.7% chance of exploitation within 30 days, higher than 54% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of unleash you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Unleashunleash< 7.5.2; >= 7.6.0, < 7.6.5; >= 8.0.0, < 8.0.2Not stated

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
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Official description

Unleash is an open-source feature management platform. Prior to 7.5.2, 7.6.5, and 8.0.2, the shared OpenAPI validation error path in src/lib/error/bad-data-error.ts passes a raw request value from lodash.get to JSON.stringify in genericErrorMessage and fromOpenApiValidationErrors without guarding stack exhaustion. An unauthenticated attacker can send a roughly 10 KB JSON value nested thousands of levels deep to POST /edge/validate, POST /edge/issue-token, or another OpenAPI-validated endpoint, causing RangeError: Maximum call stack size exceeded in openAPIValidationMiddleware and terminating the Node process because no uncaughtException handler recovers it. Replaying the request can sustain a complete service outage. This issue is fixed in versions 7.5.2, 7.6.5, and 8.0.2.

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

The underlying weakness: Uncontrolled Recursion

The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.

How developers prevent this class of flaw

  • Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.

More Uncontrolled Recursion vulnerabilities (CWE-674)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in unleash

All unleash vulnerabilities

Recent Uncontrolled Recursion vulnerabilities

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