Google Sentencepiece up to 0.2.1pre2 src/normalizer.cc DecodePrecompiledCharsMap memory corruption

Summaryinfo

A vulnerability marked as critical has been reported in Google Sentencepiece. Affected by this vulnerability is the function Normalizer::DecodePrecompiledCharsMap of the file src/normalizer.cc. The manipulation leads to memory corruption. This vulnerability is listed as CVE-2026-1260. The attack must be carried out locally. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Google Sentencepiece (Artificial Intelligence Software). This issue affects the function Normalizer::DecodePrecompiledCharsMap of the file src/normalizer.cc. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Invalid memory access in Sentencepiece versions less than 0.2.1 when using a vulnerable model file, which is not created in the normal training procedure.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-1260 since 01/20/2026. The exploitation is known to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 318116 (Fedora 45 : sentencepiece (2026-8755a17c6e)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.2.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch d856b67fdb3492e035489abf9b3aaf486144b2c0 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (318116). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Artificial Intelligence Software

Vendor

• Google

Name

• Sentencepiece

Version

• 0.1.4
• 0.1.5
• 0.1.6
• 0.1.6pre1
• 0.1.7
• 0.1.8
• 0.1.9
• 0.1.81
• 0.1.82
• 0.1.83
• 0.1.84
• 0.1.85
• 0.1.86
• 0.1.90
• 0.1.91
• 0.1.92
• 0.1.93
• 0.1.94
• 0.1.95
• 0.1.96
• 0.1.97
• 0.1.98
• 0.1.98pre1
• 0.1.99
• 0.1.99pre1
• 0.2.0
• 0.2.0pre1
• 0.2.1pre1
• 0.2.1pre2

License

• free

Website

• Vendor: https://www.google.com/
• Product: https://github.com/google/sentencepiece/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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