{"id":"UBUNTU-CVE-2026-18374","details":"Passing an effectively empty string to the `,ccs=` syntax extension of the mode argument in the `fopen` function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled. This usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for `ccs` should not pass them through without validation.","modified":"2026-11-09T12:49:51.409990279Z","published":"2026-08-27T20:17:00Z","upstream":["CVE-2026-18374"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-18374"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-18374"},{"type":"REPORT","url":"https://sourceware.org/git/?p=glibc.git;a=blob;f=advisories/GLIBC-SA-2026-0015"},{"type":"REPORT","url":"http://www.openwall.com/lists/oss-security/2026/08/27/6"}],"affected":[{"package":{"name":"eglibc","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/eglibc?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.17-93ubuntu4","2.18-0ubuntu1","2.18-0ubuntu2","2.18-0ubuntu4","2.18-0ubuntu5","2.18-0ubuntu6","2.18-0ubuntu7","2.19-0ubuntu2","2.19-0ubuntu3","2.19-0ubuntu4","2.19-0ubuntu5","2.19-0ubuntu6","2.19-0ubuntu6.1","2.19-0ubuntu6.3","2.19-0ubuntu6.4","2.19-0ubuntu6.5","2.19-0ubuntu6.6","2.19-0ubuntu6.7","2.19-0ubuntu6.8","2.19-0ubuntu6.9","2.19-0ubuntu6.10","2.19-0ubuntu6.11","2.19-0ubuntu6.13","2.19-0ubuntu6.14","2.19-0ubuntu6.15","2.19-0ubuntu6.15+esm1","2.19-0ubuntu6.15+esm2","2.19-0ubuntu6.15+esm3","2.19-0ubuntu6.15+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"eglibc-source","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"libc-bin","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"libc-dev-bin","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"libc6","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"libc6-amd64","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_version":"2.19-0ubuntu6.15+esm4","binary_name":"libc6-armel"},{"binary_name":"libc6-dev-amd64","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"libc6-dev-armel","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"libc6-dev-i386","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"libc6-dev-x32","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_version":"2.19-0ubuntu6.15+esm4","binary_name":"libc6-i386"},{"binary_name":"libc6-pic","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_version":"2.19-0ubuntu6.15+esm4","binary_name":"libc6-prof"},{"binary_version":"2.19-0ubuntu6.15+esm4","binary_name":"libc6-x32"},{"binary_name":"multiarch-support","binary_version":"2.19-0ubuntu6.15+esm4"},{"binary_name":"nscd","binary_version":"2.19-0ubuntu6.15+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18374.json"}},{"package":{"name":"glibc","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/glibc?arch=source&distro=esm-infra%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.21-0ubuntu4","2.21-0ubuntu5","2.21-0ubuntu6","2.23-0ubuntu1","2.23-0ubuntu2","2.23-0ubuntu3","2.23-0ubuntu4","2.23-0ubuntu5","2.23-0ubuntu6","2.23-0ubuntu7","2.23-0ubuntu9","2.23-0ubuntu10","2.23-0ubuntu11","2.23-0ubuntu11.2","2.23-0ubuntu11.3","2.23-0ubuntu11.3+esm1","2.23-0ubuntu11.3+esm2","2.23-0ubuntu11.3+esm3","2.23-0ubuntu11.3+esm5","2.23-0ubuntu11.3+esm6","2.23-0ubuntu11.3+esm7","2.23-0ubuntu11.3+esm8","2.23-0ubuntu11.3+esm9"],"ecosystem_specific":{"binaries":[{"binary_name":"glibc-source","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc-bin","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc-dev-bin","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc6","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc6-amd64","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_version":"2.23-0ubuntu11.3+esm9","binary_name":"libc6-armel"},{"binary_name":"libc6-dev-amd64","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc6-dev-armel","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc6-dev-i386","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_version":"2.23-0ubuntu11.3+esm9","binary_name":"libc6-dev-s390"},{"binary_version":"2.23-0ubuntu11.3+esm9","binary_name":"libc6-dev-x32"},{"binary_name":"libc6-i386","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc6-pic","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc6-s390","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_name":"libc6-x32","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_version":"2.23-0ubuntu11.3+esm9","binary_name":"locales"},{"binary_version":"2.23-0ubuntu11.3+esm9","binary_name":"locales-all"},{"binary_name":"multiarch-support","binary_version":"2.23-0ubuntu11.3+esm9"},{"binary_version":"2.23-0ubuntu11.3+esm9","binary_name":"nscd"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18374.json"}},{"package":{"name":"glibc","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/glibc?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.26-0ubuntu2","2.26-0ubuntu2.1","2.27-0ubuntu2","2.27-0ubuntu3","2.27-3ubuntu1","2.27-3ubuntu1.2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