Memory exhaustion via inflated DEFLATE in erlang-jose 1.0.01.11.12
CVE-2026-65627 Published on October 26, 2026
Decompression bomb via unbounded zlib:inflate in jose_jwe_zip:uncompress/2
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.
Vulnerability Analysis
CVE-2026-65627 can be exploited with local system access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is a Data Amplification Vulnerability?
The software does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. An example of data amplification is a "decompression bomb," a small ZIP file that can produce a large amount of data when it is decompressed.
CVE-2026-65627 has been classified to as a Data Amplification vulnerability or weakness.
Products Associated with CVE-2026-65627
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Affected Versions
potatosalad jose:- Version 1.0.0 and below 1.11.13 is affected.
- Version a7746ecd4950f85a393136e449a91dac62b5c429 and below 857eb8e7f2d33e2c9ca2189e77226561cacaf2ad is affected.