Vulnerability · Published Oct 14, 2026 · Assigned by VulnCheck

CVE-2026-110258OW2 ASM 3.0 before 9.11 Excessive Memory Allocation via Multiple RET Instructions

Medium 5.5

In plain English

A medium-severity security flaw in ASM from OW2. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.5Medium

Exploit odds (30 days)0.2%top 93.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

OW2 ASM 3.0 before 9.11 contains an excessive memory allocation vulnerability in Label.addSubroutineRetSuccessors() that fails to enforce the single-RET-per-JSR rule. Attackers can supply a crafted invalid class file with multiple RET instructions for one JSR, triggering a roughly 2 GB allocation that crashes the JVM.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	asm	no fix listed	DEBIAN-CVE-2026-110258
Debian:13	asm	no fix listed	DEBIAN-CVE-2026-110258
Debian:14	asm	9.11.1-1	DEBIAN-CVE-2026-110258
Ubuntu:22.04:LTS	asm	no fix listed	UBUNTU-CVE-2026-110258
Ubuntu:24.04:LTS	asm	no fix listed	UBUNTU-CVE-2026-110258
Ubuntu:26.04:LTS	asm	no fix listed	UBUNTU-CVE-2026-110258
Ubuntu:26.10	asm	no fix listed	UBUNTU-CVE-2026-110258

Affected products (as reported)

Vendor	Product	Versions
OW2	ASM	3.0 – before 9.11

Weakness: CWE-789 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

https://gitlab.ow2.org/asm/asm/-/merge_requests/458 patch
https://gitlab.ow2.org/asm/asm/-/commit/4dabfe0aef14f8cccb0617640a4add8fbcc4ed36 patch
https://gitlab.ow2.org/asm/asm/-/blob/ASM_9_10_1/asm/src/main/java/org/objectweb/asm/Label.java#L568 technical-description
ASM 9.11 Release Notes release-notes
VulnCheck Advisory: OW2 ASM 3.0 before 9.11 Excessive Memory Allocation via Multiple RET Instructions third-party-advisory