CVE-2026-81319

Unsafe deserialization of decrypted terms enables node DoS in AshCloak

Published Aug 30, 2026 CVSS 4.0 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
Deserialization of Untrusted Data vulnerability in ash-project ash_cloak allows an attacker who can influence the bytes of an encrypted column to crash the BEAM node, by triggering unbounded atom creation or a decompression bomb during decryption.

AshCloak.Calculations.Decrypt decodes the decrypted binary with Ash.Helpers.non_executable_binary_to_term/1 without the :safe option, so atoms in the payload are interned during the decode and never garbage collected, and the term format's compressed form is inflated transparently. vault.decrypt!() is the only barrier and stops tampering only for an authenticated cipher. Cloak also ships the unauthenticated AES.CTR, whose ciphertext an attacker who knows their own plaintext can XOR into any same-length payload without the key, so an ordinary read of the forged column reaches the decoder. A few hundred kilobytes of distinct atoms exhausts the atom table, or a small compressed payload inflates to gigabytes.

This issue affects ash_cloak: from 0.1.0 before 0.4.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Deserialization of Untrusted Data vulnerability in ash-project ash_cloak allows an attacker who can influence the bytes of an encrypted column to crash the BEAM node, by triggering unbounded atom creation or a decompression bomb during decryption. AshCloak.Calculations.Decrypt decodes the decrypted binary with Ash.Helpers.non_executable_binary_to_term/1 without the :safe option, so atoms in the payload are interned during the decode and never garbage collected, and the term format's compressed form is inflated transparently. vault.decrypt!() is the only barrier and stops tampering only for an authenticated cipher. Cloak also ships the unauthenticated AES.CTR, whose ciphertext an attacker who knows their own plaintext can XOR into any same-length payload without the key, so an ordinary read of the forged column reaches the decoder. A few hundred kilobytes of distinct atoms exhausts the atom table, or a small compressed payload inflates to gigabytes. This issue affects ash_cloak: from 0.1.0 before 0.4.0.
Title Unsafe deserialization of decrypted terms enables node DoS in AshCloak
First Time appeared Ash-project
Ash-project ash Cloak
Weaknesses CWE-502
CPEs cpe:2.3:a:ash-project:ash_cloak:*:*:*:*:*:*:*:*
Vendors & Products Ash-project
Ash-project ash Cloak
References
Metrics cvssV4_0

{'score': 5.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
EEF
Published
Updated
Sep 1, 2026, 12:32 PM
Reserved
Aug 30, 2026, 5:45 AM
Status
Deferred
Published
Aug 30, 2026, 6:16 PM
Modified
Sep 1, 2026, 9:15 PM