How severe is CVE-2017-18258?

CVE-2017-18258 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2017-18258 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-18258?

CVE-2017-18258 affects Xmlsoft Libxml2. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-18258?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-18258 published?

CVE-2017-18258 was published on 2018-04-08 and last updated on 2026-06-17.

CVE-2017-18258

CVE-2017-18258 is a medium-severity vulnerability in Xmlsoft Libxml2 with a CVSS 3.x base score of 6.5. 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-770.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Xmlsoft Libxml2
Published: 2018-04-08
Last modified: 2026-06-17

Description

The xz_head function in xzlib.c in libxml2 before 2.9.6 allows remote attackers to cause a denial of service (memory consumption) via a crafted LZMA file, because the decoder functionality does not restrict memory usage to what is required for a legitimate file.

Frequently asked questions

What is CVE-2017-18258?: The xz_head function in xzlib.c in libxml2 before 2.9.6 allows remote attackers to cause a denial of service (memory consumption) via a crafted LZMA file, because the decoder functionality does not restrict memory usage to what is required for a legitimate file.
How severe is CVE-2017-18258?: CVE-2017-18258 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2017-18258 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-18258?: CVE-2017-18258 affects Xmlsoft Libxml2. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-18258?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-18258 published?: CVE-2017-18258 was published on 2018-04-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*

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