CVE-2026-43977

wger is a free, open-source workout and fitness manager. In versions prior to 2.6, any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own. The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's. This issue has been fixed in version 2.6.

wger is a free, open-source workout and fitness manager. In versions prior to 2.6, any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own. The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's. This issue has been fixed in version 2.6.

Summary

Any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own.

The RoutinePermission class grants read access to any authenticated user when a routine has is_template=True, regardless of ownership. The /logs/ and /stats/ API actions use the same permission check but return the routine owner's personal training data instead of the requesting user's data, creating an insecure direct object reference (IDOR).

An attacker with a free account can enumerate all public template routine IDs via GET /api/v2/routine/?is_template=true, then call GET /api/v2/routine/{id}/logs/ and GET /api/v2/routine/{id}/stats/ to access the owner's private health data including workout notes, weights, repetitions, and performance statistics.

Description

wger exposes a REST API endpoint that allows any authenticated user to retrieve the private workout session notes, exercise logs, and training statistics belonging to another user, as long as that user has at least one routine marked as a public template.

The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's.

Root Cause

File: wger/manager/api/permissions.py, lines 30–41

def has_object_permission(self, request, view, obj):
    if obj.user == request.user:
        return True

    if obj.is_template:                                  # ← any template is readable
        return request.method in permissions.SAFE_METHODS  # by any authenticated user

    return False

File: wger/manager/api/views.py, lines 173–199

@action(detail=True, url_path='logs')
def logs(self, request, pk):
    out = LogDisplaySerializer(
        self.get_object().logs_display(),   # ← returns OWNER's logs, not request.user's
        many=True,
    ).data
    return Response(out)

@action(detail=True, url_path='stats')
def stats(self, request, pk):
    out = LogStatsDataSerializer(
        self.get_object().calculate_log_statistics()  # ← owner's statistics
    ).data
    return Response(out)

self.get_object() retrieves the routine belonging to the owner (e.g., user A). Since is_template=True passes the permission check for any authenticated user, the attacker's request reaches logs_display() and calculate_log_statistics(), which return the owner's workout history, not the attacker's.

The intended behavior is that templates are public workout plans (exercise structure, sets, reps), but the /logs/ and /stats/ actions expose the owner's personal training history logged against that plan.

Impact

An authenticated attacker can:

1. Enumerate all public template routines across all users: GET /api/v2/routine/?is_template=true&is_public=true

2. Read private workout session notes (freeform text entered by the victim after each workout session)

3. Read full workout history including exercise names, weights, repetitions, and dates

4. Read training statistics including volume, intensity, and set counts per muscle group and mesocycle

This data is health-related and personal. Under GDPR and similar regulations, unauthorized access to personal health data constitutes a data breach.

Proof of Concept

Scenario

There are two users in the system:

• alice : a regular wger user who has been using the platform for months. She…

wger is a free, open-source workout and fitness manager. In versions prior to 2.6, any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own. The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's. This issue has been fixed in version 2.6.

wger is a free, open-source workout and fitness manager. In versions prior to 2.6, any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own. The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's. This issue has been fixed in version 2.6.

Summary

Any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own.

The RoutinePermission class grants read access to any authenticated user when a routine has is_template=True, regardless of ownership. The /logs/ and /stats/ API actions use the same permission check but return the routine owner's personal training data instead of the requesting user's data, creating an insecure direct object reference (IDOR).

An attacker with a free account can enumerate all public template routine IDs via GET /api/v2/routine/?is_template=true, then call GET /api/v2/routine/{id}/logs/ and GET /api/v2/routine/{id}/stats/ to access the owner's private health data including workout notes, weights, repetitions, and performance statistics.

Description

wger exposes a REST API endpoint that allows any authenticated user to retrieve the private workout session notes, exercise logs, and training statistics belonging to another user, as long as that user has at least one routine marked as a public template.

The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's.

Root Cause

File: wger/manager/api/permissions.py, lines 30–41

def has_object_permission(self, request, view, obj):
    if obj.user == request.user:
        return True

    if obj.is_template:                                  # ← any template is readable
        return request.method in permissions.SAFE_METHODS  # by any authenticated user

    return False

File: wger/manager/api/views.py, lines 173–199

@action(detail=True, url_path='logs')
def logs(self, request, pk):
    out = LogDisplaySerializer(
        self.get_object().logs_display(),   # ← returns OWNER's logs, not request.user's
        many=True,
    ).data
    return Response(out)

@action(detail=True, url_path='stats')
def stats(self, request, pk):
    out = LogStatsDataSerializer(
        self.get_object().calculate_log_statistics()  # ← owner's statistics
    ).data
    return Response(out)

self.get_object() retrieves the routine belonging to the owner (e.g., user A). Since is_template=True passes the permission check for any authenticated user, the attacker's request reaches logs_display() and calculate_log_statistics(), which return the owner's workout history, not the attacker's.

The intended behavior is that templates are public workout plans (exercise structure, sets, reps), but the /logs/ and /stats/ actions expose the owner's personal training history logged against that plan.

Impact

An authenticated attacker can:

1. Enumerate all public template routines across all users: GET /api/v2/routine/?is_template=true&is_public=true

2. Read private workout session notes (freeform text entered by the victim after each workout session)

3. Read full workout history including exercise names, weights, repetitions, and dates

4. Read training statistics including volume, intensity, and set counts per muscle group and mesocycle

This data is health-related and personal. Under GDPR and similar regulations, unauthorized access to personal health data constitutes a data breach.

Proof of Concept

Scenario

There are two users in the system:

• alice : a regular wger user who has been using the platform for months. She…

Summary

Any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own.

The RoutinePermission class grants read access to any authenticated user when a routine has is_template=True, regardless of ownership. The /logs/ and /stats/ API actions use the same permission check but return the routine owner's personal training data instead of the requesting user's data, creating an insecure direct object reference (IDOR).

An attacker with a free account can enumerate all public template routine IDs via GET /api/v2/routine/?is_template=true, then call GET /api/v2/routine/{id}/logs/ and GET /api/v2/routine/{id}/stats/ to access the owner's private health data including workout notes, weights, repetitions, and performance statistics.

Description

wger exposes a REST API endpoint that allows any authenticated user to retrieve the private workout session notes, exercise logs, and training statistics belonging to another user, as long as that user has at least one routine marked as a public template.

The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's.

Root Cause

File: wger/manager/api/permissions.py, lines 30–41

def has_object_permission(self, request, view, obj):
    if obj.user == request.user:
        return True

    if obj.is_template:                                  # ← any template is readable
        return request.method in permissions.SAFE_METHODS  # by any authenticated user

    return False

File: wger/manager/api/views.py, lines 173–199

@action(detail=True, url_path='logs')
def logs(self, request, pk):
    out = LogDisplaySerializer(
        self.get_object().logs_display(),   # ← returns OWNER's logs, not request.user's
        many=True,
    ).data
    return Response(out)

@action(detail=True, url_path='stats')
def stats(self, request, pk):
    out = LogStatsDataSerializer(
        self.get_object().calculate_log_statistics()  # ← owner's statistics
    ).data
    return Response(out)

self.get_object() retrieves the routine belonging to the owner (e.g., user A). Since is_template=True passes the permission check for any authenticated user, the attacker's request reaches logs_display() and calculate_log_statistics(), which return the owner's workout history, not the attacker's.

The intended behavior is that templates are public workout plans (exercise structure, sets, reps), but the /logs/ and /stats/ actions expose the owner's personal training history logged against that plan.

Impact

An authenticated attacker can:

1. Enumerate all public template routines across all users: GET /api/v2/routine/?is_template=true&is_public=true

2. Read private workout session notes (freeform text entered by the victim after each workout session)

3. Read full workout history including exercise names, weights, repetitions, and dates

4. Read training statistics including volume, intensity, and set counts per muscle group and mesocycle

This data is health-related and personal. Under GDPR and similar regulations, unauthorized access to personal health data constitutes a data breach.

Proof of Concept

Scenario

There are two users in the system:

• alice : a regular wger user who has been using the platform for months. She…