EUVD-2026-75746
GHSA-5w42-gv46-j4rp
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Network vector for server-side file intake; no auth or interaction needed; read-only OOB access drives C:H with no write or confirmed availability impact.
Primary rating from Vendor (mitre).
CVSS VectorVendor: mitre
Lifecycle Timeline
7DescriptionCVE.org
An out-of-bounds read vulnerability exists in the xls_dumpSummary() function of libxls 1.6.3 due to insufficient validation of file-controlled OLE summary offsets.
AnalysisAI
Out-of-bounds read in libxls 1.6.3 allows a remote, unauthenticated attacker to leak heap memory contents by supplying a maliciously crafted XLS file with manipulated OLE Property Set Stream offsets. The vulnerability resides in xls_dumpSummary(), which dereferences file-controlled section and property offsets against a 4096-byte OLE summary buffer without first validating that those offsets remain within buffer bounds. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires that a target application calls xls_summaryInfo() on an attacker-supplied .xls file using libxls 1.6.3 or an unpatched prior version. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The NVD CVSS 3.1 vector AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N (7.5) is broadly consistent with the vulnerability mechanics: a crafted file processed server-side requires no authentication or user interaction, and the primary impact is confidentiality through heap memory disclosure. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | The upstream fix is available as a source patch in GitHub PR #165 (commit 6eed8bc1d51d6649faebab0184b21ab8768d8fa6) at https://github.com/libxls/libxls/pull/165/changes/6eed8bc1d51d6649faebab0184b21ab8768d8fa6; this is an upstream fix available via PR commit, and a formally tagged patched release version has not been independently confirmed at time of analysis. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all systems using libxls 1.6.3 and assess whether they process untrusted XLS files. …
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Same weakness CWE-125 – Out-of-bounds Read
View allSame technique Information Disclosure
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External POC / Exploit Code
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