--- cve: "CVE-2026-77118" severity: "HIGH" cvss: 8.4 epss: "31.3%" vendor: "Debian" kev: false exploited: false published: "2026-08-20 13:19:07" tags: [cve, security, high] source: tsecurity.de CVE-Dossier exported: "2026-09-11T07:41:45+02:00" --- # CVE-2026-77118 > 8.4 HIGH ## Beschreibung A heap out-of-bounds write exists in the Photo CD (PCD) decoder of GraphicsMagick. In DecodeImage() (coders/pcd.c), the Huffman delta loop advances its output pointer with q++ after every decoded delta and never checks it against the end of the heap-allocated luma/chroma plane buffers. The pointer is repositioned only when a sync marker introduces a new plane/row; between sync markers the run length is bounded solely by the input. A crafted PCD file that positions the pointer near the end of a plane and then supplies a long run of deltas with no intervening sync therefore walks the pointer past the end of the allocation and writes through it. Processing an untrusted PCD file — for example with gm convert or gm identify, or through any application linked against libGraphicsMagick — can corrupt heap memory beyond the buffers. ## CVSS-Vektor ``` CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N ``` | Metrik | Wert | Bewertung | |---|---|---| | AV Angriffsvektor | Lokal | good | | AC Komplexität | Gering | bad | | PR Privilegien | Keine | bad | ## Referenzen - - --- _Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-77118) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_