CVE-2026-91970Public exploitNetwork attack vectorHinoki check available

Service crash via unbounded retained attachment buffers

Published Sep 15, 2026 · Updated Sep 15, 2026

Resource exhaustion in Vikunja before 2.6.0 allows remote authenticated users to crash the shared API through a Planka migration. The asynchronous worker downloads every advertised non-link attachment into a bytes.Buffer and retains each byte slice until hierarchy insertion begins. Any ordinary account can submit one migration against an attacker-controlled public server, exhausting worker memory and terminating the shared API for all users.

CVSS severity7.1
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Resource exhaustion in Vikunja before 2.6.0 allows remote authenticated users to crash the shared API through a Planka migration. The asynchronous worker downloads every advertised non-link attachment into a bytes.Buffer and retains each byte slice until hierarchy insertion begins. Any ordinary account can submit one migration against an attacker-controlled public server, exhausting worker memory and terminating the shared API for all users.

The record

CVE
CVE-2026-91970
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Vikunja
Product
Vikunja
Classifications
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

7.1GitHub Security AdvisoryCVSS: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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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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