9.8Critical
CVE-2026-85181
CAT uses Java String.hashCode as the sole integrity check for session cookies without server-side keying, allowing attackers to forge valid checksums offline. Attackers can set the x-forwarded-for header to bypass IP binding validation and create admin sessions with full configuration access.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.7% chance of attack attempts being seen in the next 30 days, ranking above 51% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Fastnexa security experts
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Scoring
- CVSS
- 9.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CVSS v4
- 9.3
- Weakness
- CWE-565
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-03
- Last modified
- 2026-09-23
- Sources
- NVD
References
- https://github.com/dianping/cat
- https://github.com/dianping/cat/blob/3.1.0/cat-home/src/main/java/com/dianping/cat/system/page/login/service/TokenBuilder.java
- https://github.com/dianping/cat/blob/3.1.0/cat-home/src/main/java/com/dianping/cat/util/HttpUtils.java
- https://github.com/dianping/cat/issues/2384
- https://www.vulncheck.com/advisories/cat-through-3.1.0-session-cookie-forgery-via-unkeyed-hashcode-checksum