Open Zaak is an open-source data and services layer for Dutch case-oriented working. From 1.13.0 until 1.27.2, 1.28.2, and 1.29.0, _import_document_row in src/openzaak/components/documenten/tasks.py uses the attacker-controlled bestandspad CSV field without ensuring that the resolved path remains under IMPORT_DOCUMENTEN_BASE_DIR. A client with an all-authorizations application token can supply an absolute or parent-traversal path to a file readable by the Celery service account. The worker copies that file into document storage, allowing its contents to be retrieved through the normal document download API and exposing server secrets or other private files. This issue is fixed in versions 1.27.2, 1.28.2, and 1.29.0.
CVE-2026-55836
MEDIUMPre-NVD 6.86.8ElevatedEG-KEV Tier 3: ElevatedEG-KEV is EchelonGraph's own tiering of exploitation signals from CISA KEV, CISA's SSVC data (Vulnrichment), ransomware data, public exploit-code references and EPSS.Tier 3 is not evidence of exploitation. It means public exploit code is referenced, or CISA's SSVC data says "public PoC", or EPSS ranks the CVE in the top 5%.Signals for this CVE: CISA's SSVC exploitation value: public PoC.EchelonGraph confidence 38%: a heuristic from the tier and the number of signals, not a measured probability.
EchelonGraph scoreMEDIUM confidence
“—” beside the score: it is equal to the CVSS score beside it.
This medium-severity CVE scores 6.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (33rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Also known asEUVD-2026-102900 (ENISA EUVD)Source: ENISA EUVD
6.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.8Exploit: No code on recordExposed services: Not assessed
The CVE record names the fixed release — apply it.
- CVSS v3
- 6.8
- EG Score
- 6.8MEDIUMmedium confidence
- EG Risk
- 47EG Risk 47/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity68% × 45%Impact severity (EG Severity): CVSS 6.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation public PoC (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: The CVE record names the fixed release. Apply it within your standard update timelines. - EPSS PROB
- 0.4%
- EPSS %ILE
- 33rd
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (6.8): severity, escalated by confirmed exploitation. This CVE's 6.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 6.8 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
The CVE record names the fixed release. Apply it within your standard update timelines.
Exploitation public PoC (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
October 16, 2026
Last Modified
October 16, 2026
Advisory Details (4)
Auto-updated Oct 16, 2026Fix named in the CVE record. Sources: github_commit, github.
GitHub commit
commit 8acd5e59e013 (open-zaak/open-zaak)
Fix landed in open-zaak/open-zaak commit 8acd5e59e013 — awaiting tagged release
https://github.com/open-zaak/open-zaak/commit/8acd5e59e0132aa19284bf22f7b3defca279e2ceGitHub commit
commit 69c78ce2a0ed (open-zaak/open-zaak)
Fix landed in open-zaak/open-zaak commit 69c78ce2a0ed — awaiting tagged release
https://github.com/open-zaak/open-zaak/commit/69c78ce2a0edb45bec8809bc2205585c5f8a4054GitHub commit
commit 4b23957b55ab (open-zaak/open-zaak)
Fix landed in open-zaak/open-zaak commit 4b23957b55ab — awaiting tagged release
https://github.com/open-zaak/open-zaak/commit/4b23957b55ab792bc2ba1fbc5ce6918881b62ab8GitHub advisoryMentions a patch (unverified)
Path traversal / arbitrary server-file read via Documenten API document import (bestandspad) · Advisory · open-zaak/open-zaak · GitHub
https://github.com/open-zaak/open-zaak/security/advisories/GHSA-x5cj-23hr-5r54Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 17× 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.
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-25 14:18 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-18 03:29 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-16 20:13 UTCEG score recompute
- 2026-10-16 16:26 UTCEG score recompute
- 2026-10-16 15:29 UTCEG score recomputeFirst assessed: 6.8 MEDIUM
- 2026-10-16 15:27 UTCMITRE cvelistV5first tracked
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Frequently asked(5)
What is CVE-2026-55836?
CVE-2026-55836 is a medium-severity vulnerability; its CVE record was published on October 16, 2026. Open Zaak is an open-source data and services layer for Dutch case-oriented working. From 1.13.0 until 1.27.2, 1.28.2, and 1.29.0, importdocumentrow in src/openzaak/components/documenten/tasks.py uses the attacker-controlled bestandspad CSV field without ensuring that the resolved path remains…
When was the CVE record for CVE-2026-55836 published?
The CVE record for CVE-2026-55836 was published on October 16, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 16, 2026; the record at its source may have been updated since.
Is CVE-2026-55836 actively exploited?
CVE-2026-55836 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (33rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55836?
CVE-2026-55836 has a CVSS base score of 6.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55836?
The CVE record for CVE-2026-55836 names the fix: "This issue is fixed in versions 1.27.2, 1.28.2, and 1.29.0."
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-55836
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