CVE-2026-53655Public exploit

File smuggling via misapplied PAX size override

Published Jun 22, 2026 · Updated Jun 22, 2026

Interpretation conflict in Isaac Z. Schlueter tar before 7.5.16 allows attackers to hide archive members via crafted PAX headers. Header.decode unconditionally applies a pending PAX size override to intermediary L, K, or x metadata headers, moving the parser cursor by the wrong byte count. Parsing an attacker-supplied archive is sufficient; disagreement between a scanner and downstream extractor can conceal a malicious member.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Interpretation conflict in Isaac Z. Schlueter tar before 7.5.16 allows attackers to hide archive members via crafted PAX headers. Header.decode unconditionally applies a pending PAX size override to intermediary L, K, or x metadata headers, moving the parser cursor by the wrong byte count. Parsing an attacker-supplied archive is sufficient; disagreement between a scanner and downstream extractor can conceal a malicious member.

The record

CVE
CVE-2026-53655
Published
Jun 22, 2026
Updated
Jun 22, 2026
Vendor
Isaac Z. Schlueter
Product
tar
Classifications
CWE-436, T1027
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 7.5.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Isaac Z. Schlueter · tarversion=< 7.5.16

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
6.9GitHub, Inc.CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-436Interpretation Conflict
T1027Obfuscated Files or Information

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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