Medium severity · published Aug 27, 2026
CVE-2026-59321
Shared JSR-223 ScriptEngine evaluated concurrently without THREADING check
5.4
CVSS
0.2%
EPSS
No
On KEV
Description
A single ScriptEngine instance is reused for every message on a script-backed channel. For JSR-223 engines that report THREADING=null (not thread-safe, e.g. the Kotlin kts engine), concurrent message processing can corrupt engine-internal state, potentially leaking one message's payload/headers bindings into another message's script evaluation or throwing spurious exceptions.
Spring Integration 7.1.0
Spring Integration 7.0.0 - 7.0.5
Spring Integration 6.5.0 - 6.5.10
Spring Integration 6.4.0 - 6.4.12
Spring Integration 5.5.21 and earlier
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
Spring Integration · Spring
7.1.0; 7.0.0 through 7.0.5; 6.5.0 through 6.5.10; 6.4.0 through 6.4.12; through 5.5.21 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59321
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59321
Vendor Advisory
https://spring.io/security/cve-2026-59321
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