Libraw CVE-2026-20911

Remote attacker sends a specially crafted malicious image file to LibRaw (Commit 0b56545 or d20315b). Victim application processes file without user interaction required. No authentication needed. Affects any application linking vulnerable LibRaw library versions.

This represents a critical-severity vulnerability with exceptionally favorable exploitation characteristics from an attacker perspective. The CVSS vector reveals maximum exploitability: network-accessible (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). Complete confidentiality, integrity, and availability impact (C:H/I:H/A:H) enables full system compromise. Cisco Talos's dedicated vulnerability report suggests reproducible exploitation, though no public exploit identified at time of analysis. The authentication requirements not confirmed from available data nature means any application processing untrusted image files-web applications accepting user uploads, email attachment scanners, automated photo processing services-presents an attack surface. Real-world risk is elevated because LibRaw typically processes data from untrusted sources by design. The absence of CISA KEV listing and EPSS scoring (likely due to recent disclosure) should not diminish urgency; the technical characteristics alone justify immediate prioritization. Applications with internet-facing image processing capabilities should treat this as a critical patch priority regardless of current exploitation intelligence.

An attacker crafts a malicious RAW image file with manipulated Huffman table metadata designed to trigger incorrect buffer size calculations in LibRaw's HuffTable::initval function. The attacker uploads this file to a vulnerable web application's photo upload feature or sends it as an email attachment to an organization using LibRaw-based image processing in their mail gateway. When the application invokes LibRaw to generate thumbnails or extract EXIF metadata, the library allocates an undersized heap buffer based on the malformed metadata. Subsequent data writes overflow the buffer, corrupting adjacent heap structures. The attacker leverages this memory corruption to overwrite function pointers or vtable entries, redirecting execution to attacker-controlled shellcode embedded in the malicious file. With the CVSS vector indicating no authentication required and no user interaction beyond automatic file processing, successful exploitation grants the attacker code execution with the privileges of the image processing service, potentially enabling lateral movement, data exfiltration, or ransomware deployment depending on the compromised system's role.