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CVE Record

CVE-2026-9507: Session fixation vulnerability in Enhancesoft's osTicket

A session fixation vulnerability has been identified in osTicket v1.18.2. This security flaw allows an attacker to hijack a victim’s account by keeping the initial session identifier (OSTSESSID) active after a successful login. The issue lies in the fact that the application does not invalidate the pre-authentication cookie or generate a new identifier for the authenticated context. As a result, if an attacker manages to set a known session identifier in the victim’s browser, they will be able to maintain unauthorised access to the account once the victim has authenticated.

MediumCVSS 5.1Not KEV-listed Updated
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Glexia's Take moderate

Analyst readout for executives and security teams

Plain-English summary

CVE-2026-9507 affects osTicket 1.18.2. The application may keep the same session cookie after login. If an attacker can cause a victim to use a known session identifier before login, the attacker may gain access after the victim authenticates. This requires victim interaction and is rated medium severity.

Executive priority

Treat as a medium-priority identity and helpdesk access risk. Prioritize if osTicket handles sensitive tickets, privileged support workflows, or customer data. The issue requires user interaction but could expose authenticated accounts if conditions are met.

Technical view

The flaw is a session fixation issue involving OSTSESSID. osTicket 1.18.2 reportedly does not invalidate the pre-authentication cookie or issue a new identifier when moving to an authenticated session. CVSS v4.0 is 5.1 with network access, low complexity, no privileges, and user interaction required.

Likely exposure

Exposure is limited to organizations running Enhancesoft osTicket version 1.18.2. The source bundle marks other versions as unaffected by default, but administrators should verify exact installed versions and vendor guidance.

Exploitation context

No active exploitation is indicated in the provided sources, and the CVE is not in KEV. Exploitation depends on an attacker getting a known session identifier into a victim’s browser before the victim logs in.

Researcher notes

Evidence is limited to the CVE record and INCIBE advisory summary. The bundle does not name a fixed version or detailed workaround. Avoid assuming broader version impact beyond osTicket 1.18.2 unless vendor documentation confirms it.

Mitigation direction

  • Identify any osTicket 1.18.2 deployments.
  • Review the INCIBE and vendor advisory for patch or upgrade guidance.
  • Apply vendor-provided fixes when confirmed for your deployment.
  • Consider forcing session renewal and logout after remediation.
  • Monitor authentication logs for suspicious concurrent or unexpected sessions.

Validation and detection

  • Confirm the installed osTicket version is 1.18.2 or not.
  • Check whether OSTSESSID changes after successful login.
  • Review session-management configuration against vendor guidance.
  • Verify remediation in a test environment before production rollout.
  • Document affected instances and remediation status.
Prepared
Confidence
medium
Sources
3

Public sources used

Based on public source material and reviewed before publication.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CWE-38: Exact CWE lookup

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CVE-2026-9507 mapping review

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Vulnerability profile CVE Program record
Severity
Medium
CVSS
5.1 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1 CVSS vectors
3 Timeline events
1 ADP providers
2 Source links

SSVC decision data

CISA-ADP CISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

Score Version Severity Vector Exploit Impact Source
5.1 CVSS 4.0 Medium CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N — — INCIBE

Vulnerability scoring details

Base CVSS 4.0 score

5.1 Medium
CVSS 4.0 vector shape for CVE-2026-9507 Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reserved CVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE published CVE Program

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  3. CVE updated CVE Program

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ADP provider summaries

CISA-ADP CISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

Vendor Product Version / package Status
Enhancesoft osTicket 1.18.2 unaffected
Weakness

CWE details

CWE-38

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CWE-38 · source CWE mapping

Path Traversal: '\absolute\pathname\here'

Path Traversal: '\absolute\pathname\here' represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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