Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-86338. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-86338 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-86338. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-86338 using CVSS 6, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

mediumAccess Control

CVE-2026-86338

CVE-2026-86338 — Ash field policies do not filter-nil forbidden calculations and aggregates, enabling an information-disclosure oracle

Q: What is CVE-2026-86338?

CVE-2026-86338 is Ash field policies do not filter-nil forbidden calculations and aggregates, enabling an information-disclosure oracle. The supplied enrichment data classifies it as Access Control mapped to CWE-1220 CWE-1220.

Ash field_policies are documented to protect against filter-based information disclosure: when a field the actor may not see is referenced in a filter, it is replaced with an expression that evaluates to nil, so a filter cannot be used as a yes/no oracle to read a value the actor cannot see. This nilling was applied to attributes but not to calculations or aggregates. A user-supplied filter reference to a calculation or aggregate carries an Ash.Query.Calculation / Ash.Query.Aggregate struct, which the authorizer's reference replacement did not match (it only matched the Ash.Resource.* structs), so the filter ran against the real value. As a result, an actor whose field policies forbid a calculation or aggregate can still filter by it (for example filter(secret_calc == "x") or filter(comment_count == n)) and learn the value from whether rows match — an oracle that recovers field-policy-protected values one probe at a time. Filtering is commonly exposed to lower-privileged actors (for example via AshGraphql or AshJsonApi filter arguments), which is exactly the surface field policies are meant to protect. The fix routes filter references to calculations and aggregates through the same field-policy nilling as attributes. This issue affects ash: from 2.11.0-rc.0 before 3.33.4.

Published Sep 16, 2026Updated Sep 16, 2026Sources: NVD, ash-project (CNA), GitHub, GitHub Security Advisory, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

ash-project

2 products listed

CVSS base

medium

Remediation

The vendor's own words where we have them.

Upgrade ash to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
ash-project	ash	2.11.0-rc.0 to < 3.33.4	Vulnerable
ash-project	ash	0b6d93c7c4637280b46ae66ea1d2eaf013701238	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack Complexity

Low

Attack Vector

Network

Privileges Req

Low

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
6	CVSS 4.0	medium	—	—	ash-project (CNA)

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

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-1220 · Insufficient Granularity of Access Control

Modify Memory
Read Memory
Execute Unauthorized Code or Commands
Gain Privileges or Assume Identity

Mitigation: Access-control-policy protections must be reviewed for design inconsistency and common weaknesses. Access-control-policy definition and programming flow must be tested in pre-silicon, post-silicon testing.

Weakness & attack patterns

CWE-1220

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-1 · Accessing Functionality Not Properly Constrained by ACLsCAPEC-180 · Exploiting Incorrectly Configured Access Control Security Levels

T1574.010Hijack Execution Flow: ServicesFile Permissions Weakness

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /no.
Prioritize edge telemetry for network-reachable ash.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 6.0 (AV:N)
Sep 16, 2026 · NVD
Initial · CVE published
Sep 16, 2026 · NVD
Added · GHSA-h9mg-hh48-hrwv published (medium)
Sep 16, 2026 · GitHub Security Advisory
CVE published by MITRE.
Sep 16, 2026 · SOCRadar CTI

References

7 on the record

cna.erlef.org/cves/CVE-2026-86338.html
Vendor Advisory, Mitre
github.com/ash-project/ash/commit/0b6d93c7c4637280b46ae66ea1d2eaf013701238
Exploit, Third Party Advisory, Mitre
github.com/ash-project/ash/commit/b3d4503241f3deacb5ceb955e10a4fa927da0f67
Exploit, Third Party Advisory, Mitre
github.com/ash-project/ash/security/advisories/GHSA-7qr8-wrvq-566q
Exploit, Third Party Advisory
osv.dev/vulnerability/EEF-CVE-2026-86338
Vendor Advisory, Mitre
nvd.nist.gov/vuln/detail/CVE-2026-86338
NVD
github.com/advisories/GHSA-h9mg-hh48-hrwv
Exploit, Third Party Advisory

Elsewhere on this site

ash-projectevery CVE for this vendor
Access Controlsame class
CWE-1220other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-86338 is Ash field policies do not filter-nil forbidden calculations and aggregates, enabling an information-disclosure oracle, a medium vulnerability affecting ash from ash-project. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-86338. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-86338. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 6 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.