CVE-2026-91979Public exploitNetwork attack vectorHinoki check available

Authenticated service crash via unbounded archive expansion

Published Sep 15, 2026 · Updated Sep 15, 2026

Denial of service in Vikunja 2.5.0 and earlier allows remote authenticated users to crash an instance via a crafted import archive. The Vikunja-export importer checks individual ZIP entries but limits neither their aggregate expanded size nor file count and buffers attachments in memory. Any ordinary account with import access can exhaust server memory or disk with one upload, interrupting the instance for all users until an operator recovers it.

CVSS severity7.1
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Denial of service in Vikunja 2.5.0 and earlier allows remote authenticated users to crash an instance via a crafted import archive. The Vikunja-export importer checks individual ZIP entries but limits neither their aggregate expanded size nor file count and buffers attachments in memory. Any ordinary account with import access can exhaust server memory or disk with one upload, interrupting the instance for all users until an operator recovers it.

The record

CVE
CVE-2026-91979
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Vikunja
Product
Vikunja
Classifications
CWE-400, CWE-770, CWE-409, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Vikunja · Vikunjaversion=0 <2.6.0

Published CVSS scores

7.1GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-770Allocation of Resources Without Limits or Throttling
CWE-409Improper Handling of Highly Compressed Data (Data Amplification)
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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