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TI-2026-25917 Aliases CVE-2026-33524GHSA-cwq5-8pvq-j65j

Zserio: Integer Overflow in BitStreamReader and Unbounded Memory Allocation in Deserialization

Priority LOW 39CWE-789Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-789.

Summary

Zserio is a framework for serializing structured data with a compact and efficient way with low overhead. Prior to 2.18.1, a crafted payload as small as 4-5 bytes can force memory allocations of up to 16 GB, crashing any process with an OOM error (Denial of Service). This vulnerability is fixed in 2.18.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0032 25th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed zserio (ndsev): 2.18.1io.github.ndsev:zserio-runtime (Maven): 2.18.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ndsevzseriobefore 2.18.12.18.1Patch availableCNA
—io.github.ndsev:zserio-runtime (Maven)before 2.18.12.18.1Patch availableGHSA-cwq5-8pvq-j65j
  • zserio Vendorndsev Affected before 2.18.1 Fixed in 2.18.1 Patch available CNA
  • io.github.ndsev:zserio-runtime (Maven) Vendor— Affected before 2.18.1 Fixed in 2.18.1 Patch available GHSA-cwq5-8pvq-j65j

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nds-association:zserio:*:*:*:*:*:*:*:*before 2.18.1VulnerableNds-association
  • cpe:2.3:a:nds-association:zserio:*:*:*:*:*:*:*:* Versions before 2.18.1 Vulnerable ·Nds-association

Remediation

  • Fix · CNA zserio (ndsev) Fixed in 2.18.1
  • Fix · GHSA-cwq5-8pvq-j65j io.github.ndsev:zserio-runtime (Maven) Fixed in 2.18.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33524
  2. 2026-10-03 Alias added: GHSA-cwq5-8pvq-j65j

References

  • TI-2026-26046 Zserio: Integer Overflow in BitStreamReader on 32-bit platforms CVSS 3.1HIGH 7.5

Sources