CVE-2026-65627 Details
Description
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.
A denial-of-service vulnerability has been identified in Potatosalad Jose (Erlang-Jose) versions 1.0.0 prior to 1.11.13. This vulnerability allows remote attackers to exhaust a node's memory by sending a small, specially crafted JWE token that exploits the library's improper handling of DEFLATE-compressed data. The issue arises because the 'jose_jwe_zip:uncompress/2' function decompresses the JWE payload without any restrictions on the output size or inflation ratio. As a result, a few kilobytes of compressed data can inflate to hundreds of megabytes or even gigabytes, causing the Erlang VM (BEAM) to run out of memory and crash. This decompression bomb effect occurs automatically during the JWE decryption process, before the recipient has a chance to inspect or reject the payload. The vulnerability can be exploited by an attacker who possesses the recipient's public key, using common key management algorithms like RSA-OAEP or ECDH-ES, without the need for authentication or secret materials.
Users can upgrade to Potatosalad Jose version 1.11.13 or later, where this vulnerability has been fixed. Instructions for upgrading can be found on the Potatosalad Jose GitHub repository.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 26, 2026CISA-ADP
Assessed Nov 2, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-wfpv-qxp8-x5gm | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://cna.erlef.org/cves/CVE-2026-65627.html | EEF | AdvisoryBundle |
| https://github.com/potatosalad/erlang-jose/commit/857eb8e7f2d33e2c9ca2189e77226561cacaf2ad | EEF | Source CodeVendor |
| https://github.com/potatosalad/erlang-jose/commit/a7746ecd4950f85a393136e449a91dac62b5c429 | EEF | Source CodeVendor |
| https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-wfpv-qxp8-x5gm | EEF | AdvisoryExploitRemedyVendor |
| https://osv.dev/vulnerability/EEF-CVE-2026-65627 | EEF | AdvisoryBundle |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-409 | Improper Handling of Highly Compressed Data (Data Amplification) | EEF |
Affected Products
| Product | Versions |
|---|---|
| potatosalad jose | >= 1.0.0, < 1.11.13 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 2, 2026 | CVE Modified | CISA-ADP |
| Oct 26, 2026 | New CVE Received | EEF |