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Fencer Intel
high 7.5

CVE-2021-25829 json

An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3.

published 5y ago modified 4mo ago also EUVD-2021-12712

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
7.4%
EPSS 7.4% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

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.

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Exploit prediction

7.45% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25829 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 7.8 AV:N/AC:L/Au:N/C:N/I:N/A:C

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.