CVE-2026-88915
MISP Event Template Instantiation Bypasses Sharing Group and Tagging Authorization
Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates.
For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly.
The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction.
The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally.
Version affected: ≤2.5.45
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used 7.1
MISP Event Template Instantiation Bypasses Sharing Group and Tagging Authorization
Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates.
For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly.
The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction.
The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally.
Version affected: ≤2.5.45
- Record
CVE-2026-88915- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-862
- Updated
- 2026-11-02
EUVDEUVD-2026-75409 7.1
Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates.
For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly.
The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction.
The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally.
Version affected: ≤2.5.45
- Record
EUVD-2026-75409- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-46cw-r5cx-57f2 7.1
Affected versions of MISP do not consistently enforce the acting user's authorization when...
Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates.
For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly.
The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction.
The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally.
Version affected: ≤2.5.45
- Record
GHSA-46cw-r5cx-57f2- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/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 - Weakness
- CWE-862
- Updated
- 2026-11-02
NVD 7.1
Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates.
For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly.
The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction.
The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally.
Version affected: ≤2.5.45
- Record
CVE-2026-88915- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/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 - Weakness
- CWE-862
- Updated
- 2026-11-02
OSV 7.1
MISP Event Template Instantiation Bypasses Sharing Group and Tagging Authorization
Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates.
For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly.
The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction.
The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally.
Version affected: ≤2.5.45
- Record
CVE-2026-88915- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-862
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-88915 is a high vulnerability (CVSS 7.1) in Misp, published September 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 29th percentile. No source names a fixed version.