CVE-2026-110257
OW2 ASM 5.0 before 9.11 Excessive Memory Allocation via BootstrapMethods Attribute
OW2 ASM
CVSS
6.8MediumExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.17%Chance of exploitation activity in the next 30 days, higher than 6% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 9.11ASMCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
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.
Text from CVE List
Affected versions 1
- ASMaffected: 5.0 before 9.11CVE List
References 5
- gitlab.ow2.org/asm/asm/-/merge_requests/456Fixvia CVE List
- gitlab.ow2.org/asm/asm/-/commit/eb5fa95bb0670eaec2ecf9b8a3a501b48e5a967cFixvia CVE List
- vulncheck.com/advisories/ow2-asm-5.0-before-9.11-excessive-memory-allocation-via-bootstrapmethods-attributeAdvisoryvia CVE List
- gitlab.ow2.org/asm/asm/-/blob/ASM_9_10_1/asm/src/main/java/org/objectweb/asm/ClassReader.java#L3497Referencevia CVE List
- asm.ow2.io/versions.htmlReferencevia CVE List