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PatchSiren cyber security CVE debrief

CVE-2026-111274 selmf CVE debrief

A heap-based out-of-bounds read vulnerability exists in unarr through 1.1.1 in the zip_parse_extra_fields function due to an incorrect ZIP64 extra field length check. This allows attackers to supply a crafted ZIP archive that can cause a process crash. The vulnerability impacts systems or applications using unarr, and defenders should assess exposure and prioritize verification and potential updates. This includes reviewing and monitoring ZIP archive inputs for suspicious activity. The CVE record and source item provide details on the vulnerability, including its existence in unarr through 1.1.1 and the potential for a crafted ZIP archive to cause a process crash.

Vendor
selmf
Product
unarr
CVSS
MEDIUM 6.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-15
Original CVE updated
2026-10-15
Advisory published
2026-10-15
Advisory updated
2026-10-15

Who should care

Defenders responsible for systems or applications using unarr should assess exposure and prioritize verification and potential updates. This includes reviewing and monitoring ZIP archive inputs for suspicious activity.

Why it matters

Defenders should care about CVE-2026-111274 because it allows for a potential process crash via a crafted ZIP archive, impacting systems or applications using unarr. Verification, updates, and monitoring of ZIP archive inputs are necessary.

  • Potential process crashes due to crafted ZIP archives
  • Need for verification and potential updates of unarr
  • Monitoring for suspicious ZIP archive inputs

Technical summary

The zip_parse_extra_fields function in unarr through 1.1.1 does not correctly check the length of ZIP64 extra fields, allowing for a heap-based out-of-bounds read. Attackers can exploit this by providing a crafted ZIP archive with 0xFFFFFFFF sentinel values and a truncated ZIP64 record, causing the process to crash. The vulnerability exists in unarr through 1.1.1 and can be triggered by supplying a crafted ZIP archive. Defenders should prioritize verifying and updating unarr to a version beyond 1.1.1 if possible, and monitor for suspicious ZIP archive inputs.

Defensive priority

Defenders should prioritize verifying and updating unarr to a version beyond 1.1.1 if possible, and monitor for suspicious ZIP archive inputs.

Recommended defensive actions

  • Verify unarr version and update to a version beyond 1.1.1 if possible
  • Monitor for suspicious ZIP archive inputs
  • Implement input validation and error handling for ZIP archives
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, including its existence in unarr through 1.1.1 and the potential for a crafted ZIP archive to cause a process crash. However, there is limited information on actual exploitation or impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-111274 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-111274

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-111274 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-111274

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • unarr through 1.1.1 Heap Out-of-Bounds Read via zip_parse_extra_fields

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/111xxx/CVE-2026-111274.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://hackmd.io/@haind-pwn/unarr-tar-zip-oob

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://github.com/selmf/unarr/blob/b211040df83dee513362cdeb9bd87afa26fd5e38/zip/parse-zip.c

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://github.com/selmf/unarr

    Supplemental source - product

  • Source reference

    Unverified legacy reference

    URL: https://www.vulncheck.com/advisories/unarr-through-1.1.1-heap-out-of-bounds-read-via-zip-parse-extra-fields

    Supplemental source - third-party-advisory

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.