CVE-2026-5755 json
Denial of service via crafted TIFF file upload
published 2026-05-22 5 mo ago modified 2026-07-23 3 mo ago also GHSA-37j2-3vv8-cf24 , GO-2026-5835 , EUVD-2026-31427
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 15%
- public exploits
- 0
- none known
Summary
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.2, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the TIFF IFD offset in the image header before allocating memory, which allows authenticated users with file upload or posting permissions to cause a denial of service (server OOM) via uploading a crafted TIFF file or posting a URL that serves one.. Mattermost Advisory ID: MMSA-2026-00648
Patch / fix
- go github.com/mattermost/mattermost-server 10.11.15, 10.11.15+incompatible, 11.4.5, 11.4.5+incompatible, 11.5.4, 11.5.4+incompatible, 11.6.1, 11.6.1+incompatible
- Mattermost Mattermost 10.11.15, 11.4.5, 11.5.3, 11.5.4, 11.6.1, 11.7.0
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost-server | >=11.6.0, <11.6.1 >=11.5.0, <11.5.4 >=11.4.0, <11.4.5 >=10.11.0, <10.11.15 >=10.11.0+incompatible, <10.11.15+incompatible >=11.4.0+incompatible, <11.4.5+incompatible >=11.5.0+incompatible, <11.5.4+incompatible >=11.6.0+incompatible, <11.6.1+incompatible |
11.6.1 11.5.4 11.4.5 10.11.15 10.11.15+incompatible 11.4.5+incompatible 11.5.4+incompatible 11.6.1+incompatible |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-400 Uncontrolled Resource Consumption
References
Sources
- CVE List CVE-2026-5755
- GitHub Advisory GHSA-37j2-3vv8-cf24
- NVD CVE-2026-5755
- OSV GO-2026-5835
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