CVE-2026-43978VulnerabilityPublished 14 May 2026Updated 6 Nov 2026

wger: Privilege escalation via trainer-login session chaining allows gym trainer to impersonate gym manager

Affects wgerSource GCVE Database

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Authoritative record:CVE-2026-43978· High 8.1

Not known to be exploited · CVSS 8.1 High.

Data as of 6 Nov 2026, 01:20 UTC

CVSS 3.1 base score

8.1High

How severe the flaw is on the 0–10 CVSS scale.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
PyPIwger	Affected <=2.5	Fixed in–

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AI-suggested

The root cause is a logical error in the permission check condition in wger/core/views/user.py. Remediation requires correcting the permission check logic to ensure that the session flag 'trainer.identity' does not bypass permission verification and that the target-user protection applies correctly regardless of session state. Until a fix is released, restrict trainer account privileges and monitor for suspicious trainer-login activity.

Description

A privilege escalation vulnerability in wger allows a gym trainer to impersonate higher-privileged accounts such as gym managers by chaining calls to the trainer-login endpoint. This occurs because a session flag set during a legitimate trainer login bypasses permission checks on subsequent trainer-login calls, enabling unauthorized account switching. The flaw is due to a logical error in the permission check condition in the source code. Exploiting this vulnerability grants full gym administration capabilities including access to sensitive member data and management functions.

Impact

Any authenticated gym trainer can escalate their privileges to assume the identity of gym managers or general managers within the same gym. This grants full administrative control over gym operations, including viewing and modifying member data, managing contracts, configuring gym settings, and accessing personal information of other trainers and managers. The compromise of these accounts can lead to significant unauthorized data exposure and administrative misuse.

Summary

The vulnerability in wger (CVE-2026-43978) arises from improper permission checks in the trainer-login functionality. When a gym trainer switches into a low-privileged user, a session flag 'trainer.identity' is set. The permission check uses an AND condition that allows bypass if this flag is set, even if the current user lacks gym_trainer permission. Consequently, an attacker can chain trainer-login calls to escalate privileges and impersonate gym managers or general managers within the same gym. The target-user protection logic only applies when the current user has gym_trainer permission, which is not the case after the first hop, allowing further unauthorized escalations. The vulnerability affects wger versions up to 2.5.0a2 as demonstrated by a proof-of-concept.

CWE-269Improper Privilege Management (opens in a new tab)
Class weaknessLikelihood of exploit: MediumOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Operation
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design · Separation of Privilege
Follow the principle of least privilege when assigning access rights to entities in a software system.
Architecture and Design · Separation of Privilege
Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
Virtual Patching (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
V1.10.1 (opens in a new tab)
Attack patterns
Restful Privilege Elevation (opens in a new tab)
Privilege Abuse (opens in a new tab)
Privilege Escalation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 01:20 UTC

WeaknessesCWE-269

Technical details

References

Community reviews

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