How severe is CVE-2026-23879?

CVE-2026-23879 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-23879 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-23879?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-23879 have an EU (EUVD) identifier?

Yes. CVE-2026-23879 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39050.

When was CVE-2026-23879 published?

CVE-2026-23879 was published on 2026-06-24 and last updated on 2026-06-25.

CVE-2026-23879

CVE-2026-23879 is a high-severity vulnerability with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-59.

Key facts

Severity: High (CVSS 3.x base score 8.0)
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39050
Weakness: CWE-59
Published: 2026-06-24
Last modified: 2026-06-25

Description

py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Versions 1.1.2 and below contain an an arbitrary file write vulnerability, which allows symbolic links to be recreated outside the destination directory via crafted malicious symbolic link chains. When using extractall to extract an archive, the library restores these symbolic links, linking them to arbitrary directories on the host file system. During extraction, the program only checks the link arcname within the destination directory, but ignores the combined symlink path resolution. Attackers can exploit this vulnerability by constructing malicious archives, thereby bypassing the directory boundary restrictions implemented by the extractor. Subsequent extraction of regular files through these symbolic links can result in arbitrary file writes. This vulnerability may lead to remote code execution, privilege escalation, data corruption, or denial of service. This issue has been fixed in version 1.1.3.

Frequently asked questions

What is CVE-2026-23879?: py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Versions 1.1.2 and below contain an an arbitrary file write vulnerability, which allows symbolic links to be recreated outside the destination directory via crafted malicious symbolic link chains. When using extractall to extract an archive, the library restores these symbolic links, linking them to arbitrary directories on the host file system. During extraction, the program only checks the link arcname within the destination directory, but ignores the combined symlink path resolution. Attackers can exploit this vulnerability by constructing malicious archives, thereby bypassing the directory boundary restrictions implemented by the extractor. Subsequent extraction of regular files through these symbolic links can result in arbitrary file writes. This vulnerability may lead to remote code execution, privilege escalation, data corruption, or denial of service. This issue has been fixed in version 1.1.3.
How severe is CVE-2026-23879?: CVE-2026-23879 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-23879 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-23879?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-23879 have an EU (EUVD) identifier?: Yes. CVE-2026-23879 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39050.
When was CVE-2026-23879 published?: CVE-2026-23879 was published on 2026-06-24 and last updated on 2026-06-25.

References

Other CWE-59 (Improper Link Resolution Before File Access (Link Following)) vulnerabilities

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