{"id":"CVE-2026-44638","aliases":["DEBIAN-CVE-2026-44638","EUVD-2026-30411","GHSA-wpx3-h5g8-qr3w","UBUNTU-CVE-2026-44638","openSUSE-SU-2026:12420-1"],"status":"published","title":"libsixel: NULL pointer dereference","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","severity":{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00131,"percentile":0.02712,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-476","CWE-690"],"published":"2026-05-14T19:59:29Z","modified":"2026-11-05T17:27:03Z","fixes":[{"ecosystem":"Debian:14","package":"libsixel","fixed_in":["1:1.8.7-r2-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.3-3","1.10.5-1","1:1.8.7-1","1:1.8.7-2","1:1.8.7-3","1:1.8.7-4","1:1.8.7-5","1:1.8.7-6","1:1.8.7-r2-1"]},{"source":"osv","ecosystem":"Debian:13","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.5-1","1:1.8.7-1","1:1.8.7-2","1:1.8.7-3","1:1.8.7-4","1:1.8.7-5","1:1.8.7-6","1:1.8.7-r2-1"]},{"source":"osv","ecosystem":"Debian:14","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.8.7-r2-1"}]}],"versions":["1.10.5-1","1:1.8.7-1","1:1.8.7-2","1:1.8.7-3","1:1.8.7-4","1:1.8.7-5","1:1.8.7-6"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.2-1","1.5.2-2"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.2-2","1.7.3-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.2-1","1.8.2-2.1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.6-2","1.10.3-2","1.10.3-3"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.3-3","1.10.3-3build1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.5-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.5-1build1","1:1.8.7-r2-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.5-1","1.10.5-1build1"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"libsixel","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.10.5-3.1"}]}],"bundled":4}],"products":[{"vendor":"saitoha","product":"libsixel"}],"references":[{"url":"https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w","tags":["x_refsource_CONFIRM","exploit","Exploit","Vendor Advisory","advisory","report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44638.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44638","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-44638","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-44638","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-44638","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2026-33023","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-44636","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-44637","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-44638","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2026-44638","title":"libsixel: NULL pointer dereference","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","status":"published","published":"2026-05-14T19:59:29.704Z","modified":"2026-05-15T14:18:03.581Z","cvss":[{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low","assessor":"cna"}],"cwes":["CWE-476","CWE-690"],"updated_at":"2026-11-02T13:42:49.132798Z"}],"euvd":[{"id":"EUVD-2026-30411","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","status":"published","published":"2026-05-14T19:59:29Z","modified":"2026-05-15T14:18:03Z","cvss":[{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T19:04:28.872228Z"}],"nvd":[{"id":"CVE-2026-44638","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","status":"published","published":"2026-05-14T20:17:08.983Z","modified":"2026-10-26T14:10:00.13Z","cvss":[{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low","assessor":"secondary"},{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low","assessor":"primary"}],"cwes":["CWE-476","CWE-690"],"updated_at":"2026-11-02T14:12:19.39893Z"}],"osv":[{"id":"CVE-2026-44638","title":"libsixel: NULL pointer dereference","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","status":"published","published":"2026-05-14T19:59:29.704Z","modified":"2026-11-05T17:27:03.755273722Z","cvss":[{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low"}],"cwes":["CWE-476","CWE-690"],"updated_at":"2026-11-05T17:54:30.87969Z"},{"id":"DEBIAN-CVE-2026-44638","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","status":"published","published":"2026-05-14T20:17:08.983Z","modified":"2026-10-27T09:47:36.47593769Z","cvss":[{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T15:45:55.669088Z"},{"id":"UBUNTU-CVE-2026-44638","description":"libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.","status":"published","published":"2026-05-14T20:17:00Z","modified":"2026-10-17T12:58:21.038533085Z","cvss":[{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low"},{"version":"3.1","score":2.5,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T16:56:26.396868Z"},{"id":"openSUSE-SU-2026:12420-1","title":"libsixel-bash-completion-1.10.5-3.1 on GA media","description":"These are all security issues fixed in the libsixel-bash-completion-1.10.5-3.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2026-11-04T00:00:00Z","modified":"2026-11-05T17:23:17.517885405Z","updated_at":"2026-11-05T17:55:05.69587Z"}]}}