CVE-2026-65627

MEDIUM CVSS 4.0: 6.9
Updated Oct 26, 2026
Potatosalad
Parameter Value
CVSS 6.9 (MEDIUM)
Affected Versions 1.0.0 — 1.11.13
Fixed In 1.11.13
Type CWE-409
Vendor Potatosalad
Public PoC No

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in potatosalad jose (erlang-jose) allows a remote attacker to exhaust a node's memory with a small crafted JWE token. The jose_jwe_zip:uncompress/2 function in src/jwe/jose_jwe_zip.erl decompresses the DEFLATE-compressed plaintext of a JWE that carries the optional zip: DEF header by calling zlib:inflate/2 on the entire attacker-controlled stream, with no bound on the output size or the inflation ratio. Raw DEFLATE reaches ratios around 1000:1 on highly repetitive input, so a few-kilobyte token inflates to hundreds of megabytes or gigabytes in a single call.

Decompression runs automatically during decryption through jose_jwe:block_decrypt/2 (JOSE.JWE.block_decrypt/2 in Elixir), before the recipient can inspect or reject the payload. With the common asymmetric key-management algorithms (RSA-OAEP, ECDH-ES) an attacker needs only the recipient's public key to craft such a token, so no authentication or secret material is required. A single small token can exhaust the node's memory and crash the BEAM, denying service to all users.

This issue affects jose: from 1.0.0 before 1.11.13.

Attack Parameters

Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service

CVSS Vector v4.0

Weakness Type (CWE)

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Potatosalad Jose
cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*
1.0.0 1.11.13