SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-81319

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.

MEDIUM 5.9EPSS 0.23%

Does this matter?

Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0
5.9 MEDIUMCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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/M
EPSS
0.23% probability · 14th percentile
CISA KEV
Not listed
Weakness
CWE-502
Source
6b3ad84c-e1a6-4bf7-a703-f496b71e49db

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.