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CVE-2026-111127

Status: DeferredMedium (6.9)—
Severity6.9Medium · CVSS 4.0
Exploitation probability0.13 %higher than 2% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

catdoc through 0.95 contains an out-of-bounds read vulnerability in copy_unicode_string() in src/xlsparse.c that allows attackers to read past buffers via an unchecked string character count. Attackers can supply a crafted .xls file declaring 0xFFFF two-byte characters in LABEL, STRING, or SST records to disclose adjacent memory through xls2csv output or crash the process.

CVSS

Base score
6.9
Version
4.0
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.13 %
Percentile among all scored CVEs
2
Score date
10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

Vector AV:L con UI:P: el atacante aporta un .xls manipulado que el usuario abre con xls2csv; la lectura fuera de límites expone memoria adyacente o provoca un fallo. No hay ejecución de comandos.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Filter Network TrafficApplication Isolation and SandboxingExploit ProtectionUpdate SoftwareData Loss Prevention

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Catdoc Project — CatdocAI

CWEs

References

Show 4 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-111127",
  "cveTags": [],
  "metrics": {
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          "version": "2.0.3",
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          "modifiedAttackRequirements": "NOT_DEFINED",
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          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
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      "affectedData": [
        {
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          "vendor": "catdoc",
          "product": "catdoc",
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      "url": "https://github.com/vbwagner/catdoc",
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      "url": "https://github.com/vbwagner/catdoc/blob/38a2807d22ce1a08bc39b94e9072a9f8f52cd86f/src/xlsparse.c#L421-L520",
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    {
      "lang": "en",
      "value": "catdoc through 0.95 contains an out-of-bounds read vulnerability in copy_unicode_string() in src/xlsparse.c that allows attackers to read past buffers via an unchecked string character count. Attackers can supply a crafted .xls file declaring 0xFFFF two-byte characters in LABEL, STRING, or SST records to disclose adjacent memory through xls2csv output or crash the process."
    }
  ],
  "lastModified": "2026-10-16T18:25:45.343",
  "sourceIdentifier": "disclosure@vulncheck.com"
}