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Vulnerabilities

Vulnerability · CVE-2021-45960

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too…

Published Jan 1, 2022 · catalog updated Oct 14, 2026 · libexpat project

Last checked Oct 25, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2021-45960. EPSS is 4.67%. Act only if a listed version of libexpat project is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High8.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
4.67%
Remediation
Advisory link
Affected products
cpe debian/debian linux · cpe libexpat project/libexpat · cpe netapp/active iq unified manager · cpe netapp/hci baseboard management controller · cpe siemens/sinema remote connect server · cpe tenable/nessus

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe debian/debian linux10.0
  • cpe debian/debian linux11.0
  • cpe libexpat project/libexpatversion unspecified
  • cpe netapp/active iq unified managerversion unspecified
  • cpe netapp/hci baseboard management controllerh610c
  • cpe siemens/sinema remote connect serverversion unspecified
  • cpe tenable/nessusversion unspecified

How to fix CVE-2021-45960

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-2021-45960. EPSS is 4.67%. Act only if a listed version of libexpat project is installed.

Which versions are affected?

Compare what you have installed with debian/debian linux 10.0; debian/debian linux 11.0; netapp/hci baseboard management controller h610c. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-682. EPSS 4.67%. 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.

  1. Jan 1, 2022 · NIST NVD

    Detected

    In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

  2. Oct 14, 2026 · NIST NVD

    Updated

    In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

Sources

  • CVE.orgVulnerability recordCVE-2021-45960

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-45960

    30-day exploitation probability 4.67%

    first.org
  • NIST NVDVulnerability recordCVE-2021-45960

    In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 25, 2026
  • CVE.orgOct 16, 2026
  • NIST NVDOct 14, 2026