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PatchSiren cyber security CVE debrief

CVE-2026-110261 OW2 CVE debrief

A denial of service vulnerability exists in OW2 ASM 3.0 before 9.11, allowing attackers to exhaust CPU by supplying crafted class files processed with ClassWriter.COMPUTE_FRAMES. The vulnerability is caused by the unbounded MethodWriter.computeAllFrames() fix point algorithm, which can converge slowly and tie up transforming threads for an unbounded time.

Vendor
OW2
Product
ASM
CVSS
MEDIUM 6.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-14
Original CVE updated
2026-10-14
Advisory published
2026-10-14
Advisory updated
2026-10-14

Who should care

Defenders responsible for systems using OW2 ASM 3.0 before 9.11 should assess exposure and prioritize verification and potential remediation. This includes operators, platform administrators, vulnerability management teams, and security teams who need to evaluate the risk of CPU exhaustion and take appropriate actions to mitigate it.

Why it matters

Defenders should prioritize verifying exposure in systems using OW2 ASM 3.0 before 9.11 and assessing the potential for CPU exhaustion due to crafted class files processed with ClassWriter.COMPUTE_FRAMES.

  • CPU exhaustion can occur due to crafted class files
  • Transforming threads can be tied up for an unbounded time
  • Verification of exposure and potential remediation is necessary

Technical summary

The vulnerability is caused by the unbounded MethodWriter.computeAllFrames() fix point algorithm, which can converge slowly and tie up transforming threads for an unbounded time. This occurs when attackers supply crafted class files processed with ClassWriter.COMPUTE_FRAMES, leading to excessive CPU consumption. The issue affects OW2 ASM 3.0 before version 9.11. Defenders should prioritize verifying exposure and assessing potential impacts on CPU exhaustion in affected systems. Technical details indicate that crafted methods can make the algorithm converge slowly.

Defensive priority

Defenders should prioritize verifying exposure in systems using OW2 ASM 3.0 before 9.11 and assessing the potential for CPU exhaustion.

Recommended defensive actions

  • Verify exposure in systems using OW2 ASM 3.0 before 9.11
  • Assess the potential for CPU exhaustion
  • Apply patches or updates to OW2 ASM 9.11 or later
  • Monitor systems for signs of CPU exhaustion
  • Review compensating controls for exposed systems
  • Track exceptions and retest remediated assets
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, affected versions, and references to patches and technical descriptions. Defenders should verify exposure in systems using OW2 ASM 3.0 before 9.11 and assess the potential for CPU exhaustion due to crafted class files processed with ClassWriter.COMPUTE_FRAMES. Evidence is limited to CVE and source-item details.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-110261 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-110261

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-110261 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-110261

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • OW2 ASM 3.0 before 9.11 Excessive CPU Consumption via ClassWriter COMPUTE_FRAMES

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/110xxx/CVE-2026-110261.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://gitlab.ow2.org/asm/asm/-/merge_requests/463

    Supplemental source - patch

  • Source reference

    Unverified legacy reference

    URL: https://gitlab.ow2.org/asm/asm/-/commit/ab68bbd2521359b7c8cd3517c6331ced3d817ed0

    Supplemental source - patch

  • Source reference

    Unverified legacy reference

    URL: https://gitlab.ow2.org/asm/asm/-/blob/ASM_9_10_1/asm/src/main/java/org/objectweb/asm/MethodWriter.java

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://asm.ow2.io/versions.html

    Supplemental source - release-notes

  • Source reference

    Unverified legacy reference

    URL: https://www.vulncheck.com/advisories/ow2-asm-3.0-before-9.11-excessive-cpu-consumption-via-classwriter-compute-frames

    Supplemental source - third-party-advisory

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.