Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The jose4j library (Maven package org.bitbucket.b_c:jose4j) is vulnerable in versions before 0.9.6. An attacker can send a crafted JSON Web Encryption token with an extremely high compression ratio, causing heavy memory allocation and processing time during decompression and a denial of service. Upgrade to version 0.9.6 or later. The source gives few details about the exact conditions required to reach the vulnerable code path.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub Advisory Database |
- CISA KEV Not listed.
- EPSS 0.0026, the 17th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:17 UTC First seen by agentprime
- 31 Oct 2026, 14:17 UTC Confirmed by OSV