Sumatrapdfreader vulnerabilities

CVE-2026-107802 High · 7.1 CWE-88 Oct 8, 2026

SumatraPDF — Windows command-line argument injection in AI selection-translate

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, src/SelectionTranslate.cpp embeds selected or pasted translation text in quoted Windows command lines using incomplete quote-only escaping. The affected BuildGrokTranslateCmdLineTemp(), BuildClaudeTranslateCmdLineTemp(), and BuildCodexTranslateCmdLineTemp() functions can allow attacker-controlled text to inject model, working-directory, approval, or sandbox-bypass flags when the corresponding agentic CLI backend is installed and used. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

CVE-2026-107738 Medium · 6.8 CWE-125 Oct 8, 2026

SumatraPDF: Untrusted binary record offset used without lower-bound validation

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, ChmFile::GetCharZ() narrows file-controlled unsigned string offsets from /#WINDOWS and /#IVB to signed integers without a lower-bound check. An offset that becomes negative can make the function read before the /#STRINGS buffer, causing deterministic application termination. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

CVE-2026-107737 Medium · 5.7 CWE-129 Oct 8, 2026

SumatraPDF CHM `its://` signed index causes an out-of-bounds object lookup

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, and in pre-release 3.7.0.20369 when WebView2 is absent or cannot initialize, ParseProtoUrl() accepts the signed host component of an its:// URL and FindHtmlWindowById() uses it directly as an index into gHtmlWindows. Opening a crafted CHM through the IE fallback backend with a negative or otherwise out-of-range window identifier can cause an out-of-bounds pointer read followed by an invalid object callback dereference and process termination. No fixed version is available as of this review.

CVE-2026-107736 Medium · 6.8 CWE-121 Oct 8, 2026

SumatraPDF: stack buffer overflow while processing EXIF Orientation metadata

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, MaybeFlipBitmap() asks GDI+ to read the attacker-controlled PropertyTagOrientation size through GetPropertyItem() while supplying only a fixed 64-byte buf on the stack. Opening a crafted TIFF with enough EXIF Orientation values can cause attacker-selected bytes to overwrite stack control data, while tested builds terminate through the stack cookie check. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

CVE-2026-107735 Medium · 5.4 CWE-636 Oct 8, 2026

SumatraPDF: `sumatrapdfrestrict.ini` never revokes any permission (fail-open policy initialization)

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, InitializePolicies() starts the sumatrapdfrestrict.ini path with gPolicyRestrictions set to Perm::All and only ORs permission bits, so the INI file never revokes permissions. Deploying SumatraPDF with this INI file, including a malformed file or zero-valued permission settings, can silently bypass configured disk, network, printing, registry, clipboard, preference, and fullscreen restrictions. The -restrict command-line path works correctly and is not affected. No fixed version is available as of this review.

CVE-2026-107734 High · 7.1 CWE-20 Oct 8, 2026

SumatraPDF: SyncTeX Argument Injection in Inverse Search Enables Arbitrary Command Execution via External Editors

SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, an attacker-controlled SyncTeX source filename is substituted for the %f placeholder in an external editor command line without safe Windows argument quoting, and the resulting command line is passed to CreateProcessW(). A user with an external editor configured or auto-detected who opens a PDF with a crafted .synctex.gz file and invokes inverse search can inject command-line flags; the resulting impact depends on the target editor interpreting those flags and can include unintended editor actions or code execution through a malicious extension. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

CVE-2026-107733 Medium · 6.8 CWE-476 Oct 8, 2026

SumatraPDF: Null-pointer dereference in `CmdExec` when no document tab is open

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, FrameOnCommand() handles CmdExec by passing a null current-tab pointer to RunWithExe(), which dereferences WindowTab::filePath. A local process in the same interactive Windows session, at an integrity level greater than or equal to SumatraPDF's under Windows UIPI, can dispatch CmdExec over DDE or WM_COPYDATA while no document tab is open, causing abrupt process termination and loss of unsaved state. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

CVE-2026-107732 High · 8.4 CWE-94 Oct 8, 2026

SumatraPDF: Markup/command-link injection into UI notification text

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, untrusted document paths and PDF link targets are interpolated into notification text that ParseTip() interprets as trusted tip markup. When a user clicks an injected link, ExecuteTipLink() dispatches its CmdExec command and can execute an attacker-selected local program in the user's context. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

CVE-2026-107731 Medium · 5.5 CWE-125 Oct 8, 2026

SumatraPDF: LIT parser range-validation flaws cause invalid-pointer reads and denial of service

SumatraPDF is a multi-format reader for Windows. In 3.7.0.22298, four independently reachable range-validation variants in src/LitDoc.cpp allow file-controlled offsets and sizes to overflow, narrow to negative values, or wrap before incomplete bounds checks. The affected calculations include contentOffset, the directory expression dirOff64 + dirLen64, and the decoded-section offset + size, along with secondary-header range handling. Opening a crafted LIT file that reaches one of these variants can cause invalid pointer reads and deterministic application termination. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

CVE-2026-107730 Medium · 5.5 CWE-190 Oct 8, 2026

SumatraPDF: Signed integer overflow in the LIT header parsing causes invalid-pointer read

SumatraPDF is a multi-format reader for Windows. In 3.7.0.22298, LitParseHeader() in src/LitDoc.cpp computes the attacker-controlled hdrLen + nPieces * 16 section offset using signed 32-bit arithmetic without validating the complete result. When the component values make that aggregate calculation overflow to a negative value, pointer construction reaches an invalid read in LitU32(), causing deterministic application termination. The supplied evidence does not demonstrate code execution, information disclosure, arbitrary read, or integrity impact. No fixed version is available as of this review.

CVE-2026-107729 Medium · 5.5 CWE-125 Oct 8, 2026

SumatraPDF: Unsigned-to-signed hdrLen validation bypass in SumatraPDF MOBI parsing causes out-of-bounds read

SumatraPDF is a multi-format reader for Windows. In 3.7.0.22298, src/MobiDoc.cpp narrows the untrusted unsigned mobiHdr.hdrLen field to a signed integer for validation; values above INT_MAX become negative and bypass the upper-bound check. When the EXTH flag is set, the original unsigned value is reused as a pointer offset, causing DecodeExthHeader() to read beyond the record buffer. Opening a crafted MOBI file can reliably terminate the application with a native access violation; no code execution, information disclosure, or integrity impact has been demonstrated. No fixed version is available as of this review.

CVE-2026-25961 High · 7.5 Public exploit CWE-494 Feb 9, 2026

SumatraPDF Update MITM -> Arbitrary Code Execution

SumatraPDF is a multi-format reader for Windows. In 3.5.0 through 3.5.2, SumatraPDF's update mechanism disables TLS hostname verification (INTERNET_FLAG_IGNORE_CERT_CN_INVALID) and executes installers without signature checks. A network attacker with any valid TLS certificate (e.g., Let's Encrypt) can intercept the update check request, inject a malicious installer URL, and achieve arbitrary code execution.

CVE-2026-25920 Medium · 5.5 CWE-125 Feb 9, 2026

SumatraPDF has a heap out-of-bounds read in MOBI HuffDic decompressor

SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, a heap out-of-bounds read vulnerability exists in SumatraPDF's MOBI HuffDic decompressor. The bounds check in AddCdicData() only validates half the range that DecodeOne() actually accesses. Opening a crafted .mobi file can read nearly (1 << codeLength) bytes beyond the CDIC dictionary buffer, leading to a crash.

CVE-2026-25880 High · 7.8 CWE-426 Feb 9, 2026

Untrusted Search Path in SumatraPDF Reader (explorer.exe on Windows)

SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, the PDF reader allows execution of a malicious binary (explorer.exe) located in the same directory as the opened PDF when the user clicks File → “Show in folder”. This behavior leads to arbitrary code execution on the victim’s system with the privileges of the current user, without any warning or user interaction beyond the menu click.

CVE-2026-23951 Medium · 5.5 CWE-193 Jan 21, 2026

SumatraPDF's Integer Underflow in PalmDbReader Leads to Crash

SumatraPDF is a multi-format reader for Windows. All versions contain an off-by-one error in the validation code that only triggers with exactly 2 records, causing an integer underflow in the size calculation. This bug exists in PalmDbReader::GetRecord when opening a crafted Mobi file, resulting in an out-of-bounds heap read that crashes the app. There are no published fixes at the time of publication.

CVE-2026-23512 High · 7.8 CWE-426 Jan 14, 2026

SumatraPDF has an Untrusted Search Path in sumatrapdf/src/AppTools.cpp

SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, there is a Untrusted Search Path vulnerability when Advanced Options setting is trigger. The application executes notepad.exe without specifying an absolute path when using the Advanced Options setting. On Windows, this allows execution of a malicious notepad.exe placed in the application's installation directory, leading to arbitrary code execution.