CyberSecBulletin
CVE-2025-45770NVD status: Modified

Jwt: Inadequate Encryption Strength

CVE-2025-45770 is a high-severity inadequate encryption strength vulnerability in Jwt from Jwt Project, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Jwt versions: 5.4.3 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% 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. Check which version of Jwt you run against the affected versions below, and install the vendor's latest release.
  2. 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
Jwt ProjectJwt5.4.3 and earlierNot stated

Version data comes from NVD's product matching. 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
HighSuccess depends on conditions outside the attacker's control.
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
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
HighThe component can be taken down completely.

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

Official description

jwt v5.4.3 was discovered to contain weak encryption. NOTE: this issue has been disputed on the basis that key lengths are expected to be set by an application, not by this library. This dispute is subject to review under CNA rules 4.1.4, 4.1.14, and other rules; the dispute tagging is not meant to recommend an outcome for this CVE Record.

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

The underlying weakness: Inadequate Encryption Strength

The product stores or transmits sensitive data using an encryption scheme that is theoretically sound, but is not strong enough for the level of protection required.

How developers prevent this class of flaw

  • Use an encryption scheme that is currently considered to be strong by experts in the field.

More Inadequate Encryption Strength vulnerabilities (CWE-326)

Timeline

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

References

Third-party and government advisories

Other references

Recent Inadequate Encryption Strength vulnerabilities

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