CyberSecBulletin
CVE-2026-18363NVD status: Deferred

osTicket: Weak Password Recovery Mechanism for Forgotten Password

CVE-2026-18363 is a critical-severity weak password recovery mechanism for forgotten password vulnerability in osTicket from Enhancesoft, with a CVSS 4.0 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 versions 1.17.8, 1.18.4 as the first without the flaw, so updating osTicket to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update osTicket to 1.17.8 or 1.18.4, whichever matches your release line, 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
EnhancesoftosTicketbefore 1.17.8; before 1.18.41.17.8, 1.18.4

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.
Attack requirements
PresentThe target must be in a specific state or configuration for the attack to work.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
NoneNo loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (incibe.es).

Official description

A logic vulnerability in the password reset token validation routine implemented by osTicket in versions prior to v1.17.8 and v1.18.4. During the password reset process, the application retrieves the timestamp associated with the provided token and checks whether the configured validity period has expired. Consequently, the expiry check is only performed if the timestamp lookup fails, allowing tokens with an existing timestamp to bypass the intended expiry validation. Therefore, an attacker able to obtain a valid password reset token could reuse it to perform an unauthorised password reset and compromise the affected account.

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

The underlying weakness: Weak Password Recovery Mechanism for Forgotten Password

The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.

How developers prevent this class of flaw

  • Make sure that all input supplied by the user to the password recovery mechanism is thoroughly filtered and validated.
  • Do not use standard weak security questions and use several security questions.
  • Make sure that there is throttling on the number of incorrect answers to a security question. Disable the password recovery functionality after a certain (small) number of incorrect guesses.

More Weak Password Recovery Mechanism for Forgotten Password vulnerabilities (CWE-640)

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 osTicket

All osTicket vulnerabilities

Recent Weak Password Recovery Mechanism for Forgotten Password vulnerabilities

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