Medium severity · published Sep 15, 2026
CVE-2026-91979
Vikunja before 2.6.0 Denial of Service via Decompression Bomb
6.5
CVSS
0.4%
EPSS
No
On KEV
Description
Vikunja before 2.6.0 fails to limit archive expansion during data import, allowing authenticated users to cause denial of service. Attackers can upload highly compressed files that expand to tens of gigabytes in memory and disk, exhausting server resources and crashing the instance.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
VI
vikunja · go-vikunja
before 2.6.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91979
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91979
github.com
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-w7jp-mf2v-8342
www.vulncheck.com
https://www.vulncheck.com/advisories/vikunja-before-2.6.0-denial-of-service-via-decompression-bomb
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