Vulnerability · CVE-2026-9521
A security vulnerability has been detected in fraillt bitsery up to 5.2.4.
Published May 26, 2026 · catalog updated Jul 23, 2026 · A security vulnerability has
Check if you run it
No confirmed exploitation is on record for CVE-2026-9521. EPSS is 0.54%. Act only if a listed version of A security vulnerability has is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (A security vulnerability has).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Low2.9
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.54%
- Remediation
- Not established
- Affected products
- See sources for product scope
A security vulnerability has been detected in fraillt bitsery up to 5.2.4. Affected is the function loadFromSharedState in the library include/bitsery/ext/std_smart_ptr.h. Such manipulation leads to improper validation of specified type of input. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 5.2.5 is able to address this issue. The name of the patch is 66d16516e24893bebc1c8af52bf2fe9ad0735061. Upgrading the affected component is advised.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-9521
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-9521. EPSS is 0.54%. Act only if a listed version of A security vulnerability has is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-1287; CWE-20: Improper Input Validation. EPSS 0.54%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
May 26, 2026 · NIST NVD
Detected
A security vulnerability has been detected in fraillt bitsery up to 5.2.4. Affected is the function loadFromSharedState in the library include/bitsery/ext/std_smart_ptr.h. Such manipulation leads to improper validation of specified type of input. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 5.2.5 is able to address this
Jul 23, 2026 · NIST NVD
Updated
A security vulnerability has been detected in fraillt bitsery up to 5.2.4. Affected is the function loadFromSharedState in the library include/bitsery/ext/std_smart_ptr.h. Such manipulation leads to improper validation of specified type of input. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 5.2.5 is able to address this
Sources
- CVE.orgVulnerability recordCVE-2026-9521
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-9521
30-day exploitation probability 0.5%
first.org - NIST NVDVulnerability recordCVE-2026-9521
A security vulnerability has been detected in fraillt bitsery up to 5.2.4. Affected is the function loadFromSharedState in the library include/bitsery/ext/std_smart_ptr.h. Such manipulation leads to improper validation of specified type of input. It is possible to launch the atta
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.