CVE-2017-18258

Severity: medium (CVSS 6.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-04-08 · updated 2026-10-14
Weakness: CWE-770

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.

Affected products

xmlsoft libxml2: before 2.9.6 — fixed in 2.9.6

How to fix

Upgrade to a fixed version: xmlsoft libxml2 2.9.6. Check the vendor advisory for mitigations.

References

https://git.gnome.org/browse/libxml2/commit/?id=e2a9122b8dde53d320750451e9907a7dcb2ca8bb
https://kc.mcafee.com/corporate/index?page=content&id=SB10284
https://lists.debian.org/debian-lts-announce/2018/09/msg00035.html
https://lists.debian.org/debian-lts-announce/2020/09/msg00009.html
https://security.netapp.com/advisory/ntap-20190719-0001/
https://usn.ubuntu.com/3739-1/
https://git.gnome.org/browse/libxml2/commit/?id=e2a9122b8dde53d320750451e9907a7dcb2ca8bb
https://kc.mcafee.com/corporate/index?page=content&id=SB10284
https://lists.debian.org/debian-lts-announce/2018/09/msg00035.html
https://lists.debian.org/debian-lts-announce/2020/09/msg00009.html
https://security.netapp.com/advisory/ntap-20190719-0001/
https://usn.ubuntu.com/3739-1/

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