CVE-2026-110260: OW2 ASM 3.0 before 9.11 Quadratic Memory Allocation via Exception Handlers

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-14 · updated 2026-10-20
Weakness: CWE-407

Description

OW2 ASM 3.0 before 9.11 contains a quadratic memory allocation vulnerability in MethodWriter.computeMaxStackAndLocal() and computeAllFrames() when using COMPUTE_MAXS or COMPUTE_FRAMES. Attackers can supply a crafted class file with thousands of overlapping exception handlers, causing excessive Edge allocations and an OutOfMemoryError that crashes the JVM.

Affected products

OW2 ASM: from 3.0 before 9.11 — fixed in 9.11

How to fix

Upgrade to a fixed version: OW2 ASM 9.11. Check the vendor advisory for mitigations.

References

https://asm.ow2.io/versions.html
https://gitlab.ow2.org/asm/asm/-/blob/ASM_9_10_1/asm/src/main/java/org/objectweb/asm/MethodWriter.java#L1662
https://gitlab.ow2.org/asm/asm/-/commit/91057c98239d994aed5e46434e34e00d593c0daf
https://gitlab.ow2.org/asm/asm/-/merge_requests/461
https://www.vulncheck.com/advisories/ow2-asm-3.0-before-9.11-quadratic-memory-allocation-via-exception-handlers

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