Medium severity · published Oct 14, 2026
CVE-2026-110257
OW2 ASM 5.0 before 9.11 Excessive Memory Allocation via BootstrapMethods Attribute
5.5
CVSS
0.2%
EPSS
No
On KEV
Description
OW2 ASM 5.0 before 9.11 contains an excessive memory allocation vulnerability in ClassReader.readBootstrapMethodsAttribute() that sizes an int array from num_bootstrap_methods without validating attribute_length. Attackers can supply a crafted class file of about 100 bytes that forces roughly 2 GB allocation, causing an OutOfMemoryError that crashes the JVM or consuming thread.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 6% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
ASM · OW2
5.0 before 9.11 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-110257
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-110257
patch
https://gitlab.ow2.org/asm/asm/-/merge_requests/456
patch
https://gitlab.ow2.org/asm/asm/-/commit/eb5fa95bb0670eaec2ecf9b8a3a501b48e5a967c
technical-description
https://gitlab.ow2.org/asm/asm/-/blob/ASM_9_10_1/asm/src/main/java/org/objectweb/asm/ClassReader.java#L3497
release-notes
https://asm.ow2.io/versions.html
third-party-advisory
https://www.vulncheck.com/advisories/ow2-asm-5.0-before-9.11-excessive-memory-allocation-via-bootstrapmethods-attribute
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