CyberSecBulletin
CVE-2026-91995NVD status: Deferred

pig: Unverified Password Change

Published Updated By the CyberSecBulletin desk

CVE-2026-91995 is a critical-severity unverified password change vulnerability in pig from Pig-mesh, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 4.1.0 as the first without the flaw, so updating pig to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.88% chance of exploitation within 30 days, higher than 60% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update pig to 4.1.0 or a later version.
  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
Pig-meshpigbefore 4.1.04.1.0

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
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:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (vulncheck.com).

Scoring systemScoreSeverityScored by
CVSS 4.09.3CriticalCNA (vulncheck.com)
CVSS 3.19.1CriticalCNA (vulncheck.com)

Official description

pig before 4.1.0 contains an authentication bypass vulnerability in the /register/password endpoint where password verification results are discarded, allowing any value as the current password. Remote attackers can submit a username with an incorrect current password to overwrite any account credential including the admin account and gain full administrative control.

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

The underlying weakness: Unverified Password Change

When setting a new password for a user, the product does not require knowledge of the original password, or using another form of authentication.

How developers prevent this class of flaw

  • When prompting for a password change, force the user to provide the original password in addition to the new password.
  • Do not use forgotten password functionality. But if you must, ensure that you are only providing information to the actual user, e.g. by using an email address or challenge question that the legitimate user already provided in the past; do not allow the current user to change this identity information until the correct password has been provided.

More Unverified Password Change vulnerabilities (CWE-620)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Unverified Password Change vulnerabilities

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