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TI-2026-70323 Aliases CVE-2026-103636GHSA-9935-w26g-xf2m

Out-of-bounds read in Apache DataSketches VarOpt deserialization

Priority LOW 39CWE-125Published · 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
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-125 and the CVSS impact.

Summary

Apache DataSketches C++ from 2.0.0-incubating through 5.2.0 is affected. The VarOpt union deserializer reads past the end of its input when given a truncated serialized union, which is an out-of-bounds read (CWE-125). An attacker who can supply serialized data can crash the application, and the read may expose adjacent memory contents. Only applications that deserialize VarOpt unions from untrusted sources are affected.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Out-of-bounds read in the VarOpt union deserialization of Apache DataSketches C++ (repo: datasketches-cpp). var_opt_union::deserialize() read the 32-byte preamble of a non-empty union after checking that only 8 bytes were available, so a truncated serialized union could cause a read of up to 24 bytes past the end of the input. For such inputs, the size remaining for the embedded sketch was also computed by an unsigned subtraction that could wrap around, so the embedded sketch's own size checks no longer limited reads to the input. The bytes read can become part of the deserialized union's state. This can cause a crash (denial of service) and could expose adjacent memory contents. This issue affects Apache DataSketches C++: from 2.0.0-incubating before 5.3.0. Only applications that deserialize VarOpt unions from untrusted sources are affected. Users are recommended to upgrade to version 5.3.0, which fixes this issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0038 32nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

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
ApacheApache DataSketches2.0.0-incubating – 5.2.0—No fix listedCNA
  • Apache DataSketches VendorApache Affected 2.0.0-incubating – 5.2.0 Fixed in — No fix listed CNA

Remediation

Upgrade Apache DataSketches C++ to version 5.3.0, which fixes this issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Timeline

  1. 2026-10-10 Threatist record created from CVE-2026-103636
  2. 2026-10-11 Alias added: GHSA-9935-w26g-xf2m
  3. 2026-10-16 CVSS score added · CISA ADP
  4. 2026-10-16 CISA SSVC decision points changed

References

Advisory 1

Other 1

  • TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
  • TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
See all 4053 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences