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% (85th 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% (85th 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% (85th 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:*:*:*:*:*:*:*:*

More vulnerabilities in Xmlsoft Libxml2

CVE-2008-3529 — Critical (CVSS 10.0): Heap-based buffer overflow in the xmlParseAttValueComplex function in parser.c in libxml2 before 2.7.0 allows…
CVE-2004-0989 — Critical (CVSS 10.0): Multiple buffer overflows in libXML 2.6.12 and 2.6.13 (libxml2), and possibly other versions, may allow remote…
CVE-2026-6653 — Critical (CVSS 9.8): Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker…
CVE-2017-7376 — Critical (CVSS 9.8): Buffer overflow in libxml2 allows remote attackers to execute arbitrary code by leveraging an incorrect limit for port…
CVE-2017-7375 — Critical (CVSS 9.8): A flaw in libxml2 allows remote XML entity inclusion with default parser flags (i.e., when the caller did not request…
CVE-2017-16931 — Critical (CVSS 9.8): parser.c in libxml2 before 2.9.5 mishandles parameter-entity references because the NEXTL macro calls the…

All CVEs affecting Xmlsoft Libxml2 →

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

CVE-2026-63299 — Critical (CVSS 9.9): An authorization bypass vulnerability in LXD allows an authenticated user to bypass project-level disk and volume…
CVE-2026-82439 — Critical (CVSS 9.8): Description The DRPC server kept a map from function name to request queue and created an entry the first time…
CVE-2026-47891 — Critical (CVSS 9.8): A Spring WebFlux application that relies on the Aalto XML processor to parse XML input does not correctly enforce the…
CVE-2026-74878 — Critical (CVSS 9.8): openssl_encrypt versions before 1.4.0 use an in-memory rate limiter for TOTP brute-force protection that is not shared…
CVE-2026-31283 — Critical (CVSS 9.8): In Totara LMS v19.1.5 and before, the forgot password API does not implement rate limiting for the target email…
CVE-2020-37067 — Critical (CVSS 9.8): Filetto 1.0 FTP server contains a denial of service vulnerability in the FEAT command processing that allows attackers…

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