Skip to content
Noroxi
NVD / CVE Program· CNA EEF

CVE-2026-82741: Ash.Type.Union with :map_with_tag does not force the tag on dump, enabling tag confusion

Noroxi assessment

Priority: Monitor (action score 8/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: ash-project ash 3.32.2, 8dbdaecd0f115f52e7c3f9a3e798617d6fbf5f7d.

Low priority for now. Upgrade to ash-project ash 3.32.2, 8dbdaecd0f115f52e7c3f9a3e798617d6fbf5f7d or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Improper Validation of Specified Type of Input vulnerability in ash-project ash lets an attacker confuse the stored type tag of an Ash.Type.Union value that uses storage: :map_with_tag, bypassing that member's validation and any tag-based authorization. For a union with storage: :map_with_tag, each member is identified in storage by a configured tag and tag_value. Ash.Type.Union.dump_to_native/2 (lib/ash/type/union.ex) did not force the configured tag when writing the value, so a tag carried in the submitted value was persisted verbatim. An attacker can therefore store a value whose data belongs to one member but whose tag names a different member. On read the value is re-selected by its tag and treated as the incompatible member (a type confusion), bypassing the real member's constraints and any logic or policy that branches on the union tag. The fix drops any incoming tag and forces the configured tag value on dump. This issue affects ash: from 2.14.18 before 3.32.2.

LowCVSS 2.1 · v4.0—No exploit Fix available
Published
Sep 1, 2026
Updated
Sep 1, 2026
EPSS
0.1% · 8th percentile

Report tools

JSON

Action score

8

Monitor

Low priority for now.

CVSS
8 / 40 · 2.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · EEF
2.1
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-82741

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for ash-project records
Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (EEF). Independent of NVD's CPE analysis and usually ahead of it.

  • ash-project ash

    • 2.14.18 and later · before 3.32.2affected · semver
    • b0bd2d23d979e731610327636f51da4981fcef68 and later · before 8dbdaecd0f115f52e7c3f9a3e798617d6fbf5f7daffected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Hexashfrom 2.14.18 · before 3.32.23.32.2

Same product

ash-project: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-48044Authorization bypass when bypass policy condition evaluates to true
    34Monitor
  • CVE-2025-48043Bypass and runtime policies that can never pass may be incorrectly applied in filter authorization
    34Monitor
  • CVE-2026-94201Filtering an :atom attribute with unsafe_to_atom? can exhaust the BEAM atom table in Ash
    32Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-82739Sep 1, 2026 · Ash.Resource.Validation.Confirm leaks a confirmed field's stored value in the atomic mismatch error
    8Monitor
  • ← EarlierCVE-2026-82740Sep 1, 2026 · Ash.Type ignores outer array constraints on nested {:array, {:array, type}} inputs
    8Monitor
  • Later →CVE-2026-82742Sep 1, 2026 · Ash.Filter.Runtime materializes a combinatorial cross-product over to-many relationships, exhausting memory
    23Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
ash-project ash3.32.2Vendor (CNA)
ash-project ash8dbdaecd0f115f52e7c3f9a3e798617d6fbf5f7dVendor (CNA)
Hex:ash3.32.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-1287 · Improper Validation of Specified Type of Input

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records