CVE-2026-91979

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-15. A secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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 v3
6.5
EG Score
6.5MEDIUMhigh confidence
EG Risk
29
EG Risk 29/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
The EG Score, 6.5 of 10.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
35th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 15, 2026

Last Modified

September 17, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
Patch available. Sources: github.
Web page

Vikunja before 2.6.0 Denial of Service via Decompression Bomb | Advisories | VulnCheck

https://www.vulncheck.com/advisories/vikunja-before-2.6.0-denial-of-service-via-decompression-bomb
GitHub advisoryMentions a patch (unverified)

Denial of service via decompression bomb in the data import · Advisory · go-vikunja/vikunja · GitHub

https://github.com/go-vikunja/vikunja/security/advisories/GHSA-w7jp-mf2v-8342

Vendor Advisories for CVE-2026-91979(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFix by version rangeDependents
code.vikunja.io/api—
  • every version up to 2.6.0: fixed in 2.6.0
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 22× in last 7d / 77× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-11 19:13 UTCEG score recompute
  2. 2026-10-11 16:27 UTCEG score recompute
  3. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  4. 2026-10-11 13:44 UTCEG score recompute
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  6. 2026-10-09 20:27 UTCEG score recompute
  7. 2026-10-09 20:27 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  8. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  9. 2026-10-08 22:38 UTCEG score recompute
  10. 2026-10-08 22:38 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  11. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  13. 2026-10-07 22:46 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  14. 2026-10-07 00:57 UTCEG score recompute
  15. 2026-10-07 00:57 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  17. 2026-10-06 02:51 UTCEG score recompute
  18. 2026-10-06 02:51 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  19. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  20. 2026-10-05 05:02 UTCEG score recompute
  21. 2026-10-05 05:02 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  22. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-10-04 07:13 UTCEG score recompute
  24. 2026-10-04 07:13 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  25. 2026-10-03 09:24 UTCEG score recompute
Show 52 more
  1. 2026-10-03 09:24 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  2. 2026-10-02 10:18 UTCEG score recompute
  3. 2026-10-02 10:18 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  4. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  5. 2026-10-01 12:29 UTCEG score recompute
  6. 2026-10-01 12:29 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  7. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  8. 2026-09-30 14:41 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  9. 2026-09-29 16:25 UTCEG score recompute
  10. 2026-09-29 16:24 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  11. 2026-09-28 18:31 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  12. 2026-09-27 20:35 UTCEG score recompute
  13. 2026-09-27 20:35 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  14. 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  15. 2026-09-26 22:46 UTCEG score recompute
  16. 2026-09-26 22:46 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  17. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  18. 2026-09-26 00:58 UTCEG score recompute
  19. 2026-09-26 00:58 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  20. 2026-09-25 03:05 UTCEG score recompute
  21. 2026-09-25 03:05 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  22. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-09-24 05:10 UTCEG score recompute
  24. 2026-09-24 05:10 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  25. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  26. 2026-09-23 07:21 UTCEG score recompute
  27. 2026-09-23 07:21 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  28. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  29. 2026-09-22 09:33 UTCEG score recompute
  30. 2026-09-22 09:33 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  31. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  32. 2026-09-21 11:44 UTCEG score recompute
  33. 2026-09-21 11:44 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  34. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  35. 2026-09-20 13:55 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  36. 2026-09-19 16:06 UTCEG score recompute
  37. 2026-09-19 16:06 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  38. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  39. 2026-09-18 18:17 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  40. 2026-09-17 20:29 UTCEG score recompute
  41. 2026-09-17 20:29 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  42. 2026-09-17 19:39 UTCEG score recompute
  43. 2026-09-17 19:39 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  44. 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  45. 2026-09-17 19:22 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  46. 2026-09-16 21:07 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  47. 2026-09-16 14:21 UTCEG score recompute
  48. 2026-09-16 14:21 UTCGHSA enrichmentGHSA-p4h8-xg7f-xqrc · GitHub severity HIGH · GitHub CVSS 6.5
  49. 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  50. 2026-09-15 16:32 UTCEG score recompute
  51. 2026-09-15 15:23 UTCEG score recomputeFirst assessed: 6.5 MEDIUM
  52. 2026-09-15 15:22 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-91979?
CVE-2026-91979 is a medium-severity vulnerability; its CVE record was published on September 15, 2026. 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.
When was CVE-2026-91979 made public?
CVE-2026-91979 was made public on August 31, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on September 15, 2026. EchelonGraph's copy of the record carries a last-modified date of September 17, 2026; the record at its source may have been updated since.
Is CVE-2026-91979 actively exploited?
CVE-2026-91979 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-91979?
CVE-2026-91979 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-91979?
A fix for CVE-2026-91979 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-91979 are linked in the Vendor Advisories panel on this page.

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