high 7.8

CVE-2026-88053 json

Tesseract: Heap out-of-bounds write in Classify::ReadIntTemplates via unvalidated counts in crafted .traineddata

published 2026-09-10 59 d ago modified 2026-09-16 54 d ago also EUVD-2026-75630

cvss: 7.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits: 0; none known

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.

Patch / fix

distros 4 links 1

ubuntu opensuse almalinux rocky linux

tesseract Ubuntu Pro 18.04 LTS 4.00~git2288-10f4998a-2ubuntu0.1~esm1
tesseract Ubuntu Pro 20.04 LTS 4.1.1-2ubuntu0.1~esm1
tesseract Ubuntu Pro 22.04 LTS 4.1.1-2.1ubuntu0.1~esm1
tesseract Ubuntu Pro 24.04 LTS 5.3.4-1ubuntu0.1~esm1
tesseract Ubuntu Pro 26.04 LTS 5.5.0-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2026-88053

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

tesseract-ocr openSUSE Leap 16.0 5.5.3-bp160.2.1
tesseract-ocr openSUSE Leap 16.0 5.5.3-bp160.1.1
tesseract-ocr openSUSE Tumbleweed 5.5.3-2.1

opensuse advisories openSUSE-RU-2026:22002-1 openSUSE-SU-2026:21957-1 openSUSE-SU-2026:11887-1

tesseract AlmaLinux 8 4.1.1-7.el8_10
tesseract AlmaLinux 10 5.3.4-11.el10_2

almalinux advisories ALSA-2026:95725 ALSA-2026:95085

tesseract Rocky Linux 8 4.1.1-7.el8_10
tesseract Rocky Linux 9 4.1.1-11.el9_8
tesseract Rocky Linux 10 5.3.4-11.el10_2

rocky linux advisories RLSA-2026:95725 RLSA-2026:95086 RLSA-2026:95085

github.com/tesseract-ocr/tesseract@8b05746 commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-88053 updated 2026-11-09 cvss 8.4

tesseract: Tesseract: Heap out-of-bounds write leads to heap corruption via crafted data file

Red Hat Enterprise Linux AppStream (v. 8) tesseract 4.1.1-7.el8_10
fixed: vendor fix RHSA-2026:95725
Red Hat Enterprise Linux AppStream (v. 9) tesseract 4.1.1-11.el9_8
fixed: vendor fix RHSA-2026:95086
Red Hat Enterprise Linux AppStream (v. 10) tesseract 5.3.4-11.el10_2
fixed: vendor fix RHSA-2026:95085
Red Hat Enterprise Linux AppStream AUS (v.8.6) tesseract 4.1.1-2.el8_6.3
fixed: vendor fix RHSA-2026:96239
Red Hat Enterprise Linux AppStream E4S (v.8.8) tesseract 4.1.1-2.el8_8.3
fixed: vendor fix RHSA-2026:96238
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) tesseract 4.1.1-2.el8_6.3
fixed: vendor fix RHSA-2026:96239
Red Hat Enterprise Linux AppStream TUS (v.8.8) tesseract 4.1.1-2.el8_8.3
fixed: vendor fix RHSA-2026:96238
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) tesseract-devel 4.1.1-11.el9_8, tesseract-debuginfo 4.1.1-11.el9_8, tesseract-debugsource 4.1.1-11.el9_8, tesseract-tools-debuginfo 4.1.1-11.el9_8
fixed: vendor fix RHSA-2026:95086

show 2 more

Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) tesseract-devel 5.3.4-11.el10_2, tesseract-debuginfo 5.3.4-11.el10_2, tesseract-debugsource 5.3.4-11.el10_2, tesseract-tools-debuginfo 5.3.4-11.el10_2
fixed: vendor fix RHSA-2026:95085
Red Hat Enterprise Linux CRB (v. 8) tesseract-devel 4.1.1-7.el8_10, tesseract-debuginfo 4.1.1-7.el8_10, tesseract-debugsource 4.1.1-7.el8_10
fixed: vendor fix RHSA-2026:95725

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 59 d ago (2026-09-11)

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-rphx-x795-5qjv referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.6	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA	4.0	8.6	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

tesseract-ocr tesseract

Classification

Weakness

CWE-787 Out-of-bounds Write

References

github.com /tesseract-ocr/tesseract/commit/8b0574680f3b22f246ade6a4c8e3029104255c63
patch
github.com /tesseract-ocr/tesseract/security/advisories/GHSA-rphx-x795-5qjv
exploit, mitigation, vendor-advisory

Sources

CVE List CVE-2026-88053
NVD CVE-2026-88053

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary