Vulnerability · Published Oct 14, 2026 · Assigned by VulnCheck
CVE-2026-110259OW2 ASM 3.0 before 9.11 Uncontrolled Recursion via ClassWriter.replaceAsmInstructions()
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.
Official description
OW2 ASM 3.0 before 9.11 contains an uncontrolled recursion vulnerability in ClassWriter.replaceAsmInstructions() that allows attackers to cause denial of service through crafted class files. Attackers can supply a class with a large method containing many long forward jumps, triggering unbounded toByteArray() recursion and a StackOverflowError during transformation.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | asm | no fix listed | DEBIAN-CVE-2026-110259 |
| Debian:13 | asm | no fix listed | DEBIAN-CVE-2026-110259 |
| Debian:14 | asm | 9.11.1-1 | DEBIAN-CVE-2026-110259 |
| Ubuntu:22.04:LTS | asm | no fix listed | UBUNTU-CVE-2026-110259 |
| Ubuntu:24.04:LTS | asm | no fix listed | UBUNTU-CVE-2026-110259 |
| Ubuntu:26.04:LTS | asm | no fix listed | UBUNTU-CVE-2026-110259 |
| Ubuntu:26.10 | asm | no fix listed | UBUNTU-CVE-2026-110259 |
Affected products (as reported)
Weakness: CWE-674 · 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/459 patch
- https://gitlab.ow2.org/asm/asm/-/commit/e9aca627c17e1619bcb8059afb43382dac6b275f patch
- https://gitlab.ow2.org/asm/asm/-/blob/ASM_9_10_1/asm/src/main/java/org/objectweb/asm/ClassWriter.java#L751 technical-description
- ASM 9.11 Release Notes release-notes
- VulnCheck Advisory: OW2 ASM 3.0 before 9.11 Uncontrolled Recursion via ClassWriter.replaceAsmInstructions() third-party-advisory