CVE-2021-35516

CVE-2021-35516 is a high-severity vulnerability in Apache Commons Compress with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-770.

Key facts

Description

When reading a specially crafted 7Z archive, Compress can be made to allocate large amounts of memory that finally leads to an out of memory error even for very small inputs. This could be used to mount a denial of service attack against services that use Compress' sevenz package.

Frequently asked questions

What is CVE-2021-35516?
When reading a specially crafted 7Z archive, Compress can be made to allocate large amounts of memory that finally leads to an out of memory error even for very small inputs. This could be used to mount a denial of service attack against services that use Compress' sevenz package.
How severe is CVE-2021-35516?
CVE-2021-35516 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-35516 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-35516?
CVE-2021-35516 primarily affects Apache Commons Compress. In total, 47 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-35516?
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.
When was CVE-2021-35516 published?
CVE-2021-35516 was published on 2021-07-13 and last updated on 2026-06-17.

References

Affected products (47)

More vulnerabilities in Apache Commons Compress

All CVEs affecting Apache Commons Compress →

Other CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities

Browse all CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities →