CVE-2026-59679
fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) indexes the per-character encoding[] array using num_chars from the F
CVSS
9.0
Critical
EPSS
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KEV
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Exploit Today
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0-100
Published: Sep 10, 2026 · Last modified: Sep 10, 2026 · CWE-787
Not enough EPSS history yet.
fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) indexes the per-character encoding[] array using num_chars from the FS_QueryXBitmaps16 reply, but that array was allocated with a size derived from num_extents in the separate FS_QueryXExtents16 reply. The two CARD32 fields are never cross-checked. A malicious or compromised font server can send a small num_extents (e.g. 1) in the extents reply, then a large num_chars (e.g. 100000) in the bitmaps reply. This causes attacker-controlled out-of-bounds heap read and writes.
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-457707.5 HIG—
———Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Starting in version 8.0.0 and prior to version 8.0.5, a Lua rule that registers too many flow variables can corrupt Lua detection state and may bypass Suricata's restricted Lua sandbox. This requires an affected Lua script/rule to be loaded. Excessive flow variables being registered may also cause Suricata to crash. Version 8.0.5 contains a fix. As a workaround, disable `security.lua.allow-rules` unless Lua rules are required.9hCVE-2026-88053——
———Tesseract is an open source OCR engine. In version 5.5.3 and earlier, Classify::ReadIntTemplates in src/classify/intproto.cpp reads NumClassPruners, NumClasses, and NumProtoSets from the TESSDATA_INTTEMP component of a crafted .traineddata file and uses those values as loop bounds without validating them against MAX_NUM_CLASS_PRUNERS, MAX_NUM_CLASSES, and MAX_NUM_PROTO_SETS. The loops store heap pointers into fixed-capacity ClassPruners and ProtoSets arrays in INT_TEMPLATES_STRUCT and INT_CLASS_STRUCT, so an oversized count causes heap out-of-bounds pointer writes during legacy-classifier initialization before OCR begins, resulting in heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.12hCVE-2026-880527.8 HIG—
———Tesseract is an open source OCR engine. In version 5.5.3 and earlier, UNICHARSET::load_via_fgets in src/ccutil/unicharset.cpp trusts the declared unichar count as a loop bound and uses id as an unchecked index into the unichars vector. unichar_insert_backwards_compatible can leave the vector unchanged for an empty, duplicate, or already-encodable representation, causing id to become larger than unichars.size(). Subsequent set_* calls and the write to unichars[id].properties.enabled then write UNICHAR_PROPERTIES beyond the vector during initialization in both the default LSTM and legacy engines, causing heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.12hCVE-2026-88051——
———Tesseract is an open source OCR engine. In version 5.5.3 and earlier, the callback form of GenericVector::read in src/ccutil/genericvector.h reads the independent int32 fields reserved and size_used_ from a .traineddata model without a cap or an invariant check. reserve(reserved) allocates the backing array, but the callback loop writes size_used_ elements. A crafted TESSDATA_INTTEMP component with version_id 4 or later can therefore set reserved to a small value and size_used_ to a large value when fontinfo_table_.read(fp, read_info) is called from src/classify/intproto.cpp, causing a heap out-of-bounds write of FontInfo structures, heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.12hCVE-2026-88050——
———Tesseract is an open source OCR engine. In version 5.5.3 and earlier, RecodedCharID::DeSerialize in src/ccutil/unicharcompress.h validates length_ but accepts negative code_ values from a crafted .traineddata recoder component. UnicharCompress::ComputeCodeRange in src/ccutil/unicharcompress.cpp can consequently produce code_range_ equal to zero, after which SetupDecoder indexes is_valid_start_ with the negative code on a size-zero vector. The resulting out-of-bounds bit write uses a large wrapped index and reliably causes a wild-address crash or allocation failure on the default LSTM engine. No fixed release is available as of this review.12hCVE-2026-88049——
———Tesseract is an open source OCR engine. In version 5.5.3 and earlier, prior .traineddata hardening added bounds checks to NetworkIO::CopyTimeStepGeneral and NetworkIO::Randomize in src/lstm/networkio.cpp but left NetworkIO::WriteTimeStepPart and NetworkIO::AddTimeStepPart unchecked. In LSTM::Forward in src/lstm/lstm.cpp, source_ is sized from the independently deserialized na_ field while the WriteTimeStepPart count is ns_, which comes from the CI gate WeightMatrix dim1() value. A crafted NT_LSTM layer can make ns_ much larger than na_, causing a heap out-of-bounds write during the first recognition step on the default LSTM engine and resulting in heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.12h