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CVE-2021-25829An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug,…
- 7.5HighCVSS base score
- 7.4%Exploitation in 30 daysEPSS · top 5.5% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. Using this bug, an attacker is able to produce a denial of service attack that can eventually shut down the target server.
Timeline
ID reserved
By mitre
- 38 days later
· 38 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 7.4% · top 5.5% of all CVEs (13 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
n/a
- affected n/a
References
References10
- https://github.com/ONLYOFFICE/DocumentServer (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core/blob/v5.6.4.10/ASCOfficePPTXFile/Editor/BinaryFileReaderWriter.cpp#L1722 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core/blob/c1e4a2ce33bdcfab29d670f5fdb10fc63cf5fd6a/ASCOfficePPTXFile/PPTXFormat/Comments.h#L299 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core/blob/c1e4a2ce33bdcfab29d670f5fdb10fc63cf5fd6a/ASCOfficePPTXFile/PPTXFormat/Core.h#L161 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core/blob/c1e4a2ce33bdcfab29d670f5fdb10fc63cf5fd6a/ASCOfficePPTXFile/PPTXFormat/NotesMaster.h#L148 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core/blob/c1e4a2ce33bdcfab29d670f5fdb10fc63cf5fd6a/ASCOfficePPTXFile/PPTXFormat/NotesSlide.h#L141 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core/blob/c1e4a2ce33bdcfab29d670f5fdb10fc63cf5fd6a/ASCOfficePPTXFile/PPTXFormat/Presentation.h#L277 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ONLYOFFICE/core/blob/c1e4a2ce33bdcfab29d670f5fdb10fc63cf5fd6a/ASCOfficePPTXFile/PPTXFormat/Theme.h#L277 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25829 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-12712 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-25829)Record last updated .