CVE-2026-109380
modern-tar 0.3.5 through 0.8.5 Memory Exhaustion via Malformed Octal Size Field
ayuhito modern-tar
CVSS
8.7HighExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.45%Chance of exploitation activity in the next 30 days, higher than 37% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
What fixes it
No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.
Description
modern-tar 0.3.5 through 0.8.5 contains a memory exhaustion vulnerability that allows attackers to produce negative entry sizes via non-octal bytes parsed by readOctal(). Attackers can supply a crafted, optionally gzip-compressed, archive to unpackTar() that buffers chunks indefinitely, exhausting process memory and suppressing later entries.
Text from CVE List
Affected versions 1
- modern-taraffected: 0.3.5 through 0.8.5CVE List
References 5
- github.com/ayuhito/modern-tar/pull/195Fixvia CVE List
- github.com/ayuhito/modern-tar/commit/181c8cb75351867535057817ada4802a90fe416eFixvia CVE List
- vulncheck.com/advisories/modern-tar-0.3.5-through-0.8.5-memory-exhaustion-via-malformed-octal-size-fieldAdvisoryvia CVE List
- github.com/ayuhito/modern-tar/blob/v0.8.5/src/tar/encoding.tsReferencevia CVE List
- github.com/ayuhito/modern-tarReferencevia CVE List