DescriptionThe malloc function in the GNU C Library (aka glibc or libc6) 2.26 could return a memory block that is too small if an attempt is made to allocate an object whose size is close to SIZE_MAX, potentially leading to a subsequent heap overflow. This occurs because the per-thread cache (aka tcache) feature enables a code path that lacks an integer overflow check.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
NVD severitymedium

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
glibc (PTS)stretch2.24-11+deb9u4fixed
stretch (security)2.24-11+deb9u1fixed
bookworm, sid2.32-4fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
eglibcsource(unstable)(not affected)
glibcsource(unstable)(not affected)


- glibc <not-affected> (Issue introduced in glibc-2.26 with addition of per-thread cache to malloc)
- eglibc <not-affected> (Issue introduced in glibc-2.26 with addition of per-thread cache to malloc)
Introduced by:;h=d5c3fafc4307c9b7a4c7d5cb381fcdbfad340bcc
Fixed by:;h=34697694e8a93b325b18f25f7dcded55d6baeaf6
The upload of 2.26-0experimental2 to experimental fixed the issue (cf. #883729).

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