Cyber Posture

CVE-2026-4775

High

Published: 24 March 2026

Published
24 March 2026
Modified
07 May 2026
KEV Added
Patch
CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0004 13.8th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4775 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 13.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Client Execution (T1203) and 2 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates the signed integer overflow in libtiff by requiring timely remediation through patching as detailed in Red Hat and Debian advisories.

prevent

Requires validation of TIFF file inputs to detect and reject specially crafted files that trigger the overflow in putcontig8bitYCbCr44tile.

prevent

Implements memory protections like heap guards and ASLR to mitigate out-of-bounds heap writes from the integer overflow exploitation.

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1204.002 Malicious File Execution
An adversary may rely upon a user opening a malicious file in order to gain execution.
T1566.001 Spearphishing Attachment Initial Access
Adversaries may send spearphishing emails with a malicious attachment in an attempt to gain access to victim systems.
Why these techniques?

The CVE describes a client-side memory corruption vulnerability in libtiff that is triggered by opening a malicious TIFF file, directly enabling exploitation for client execution (T1203), user execution via malicious file (T1204.002), and delivery via spearphishing attachment (T1566.001).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A flaw was found in the libtiff library. A remote attacker could exploit a signed integer overflow vulnerability in the putcontig8bitYCbCr44tile function by providing a specially crafted TIFF file. This flaw can lead to an out-of-bounds heap write due to…

more

incorrect memory pointer calculations, potentially causing a denial of service (application crash) or arbitrary code execution.

Deeper analysisAI

CVE-2026-4775 is a signed integer overflow vulnerability in the libtiff library, specifically within the putcontig8bitYCbCr44tile function. Published on 2026-03-24, the flaw arises from incorrect memory pointer calculations when processing a specially crafted TIFF file, leading to an out-of-bounds heap write. Affected software includes applications and systems that rely on libtiff for TIFF image processing, such as image viewers, converters, or libraries in distributions like Red Hat and Debian. The vulnerability is classified under CWE-190 with a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating high impact potential.

A remote attacker can exploit this vulnerability by tricking a user into opening a malicious TIFF file with an affected libtiff-based application. The attack requires local access to execute the file but no privileges (PR:N) and involves user interaction (UI:R), such as clicking to view an image attachment. Successful exploitation could result in denial of service via application crash or arbitrary code execution, granting high confidentiality, integrity, and availability impacts.

Red Hat advisories RHSA-2026:12265, RHSA-2026:12271, and the CVE security page detail patches for affected libtiff versions in Red Hat Enterprise Linux. Debian LTS announcement from April 2026 addresses the issue in their long-term support packages. Security practitioners should update libtiff libraries via these errata and vendor channels, validate TIFF inputs, and consider sandboxing image processing applications to mitigate risks.

Details

CWE(s)

Affected Products

libtiff
libtiff
all versions
redhat
hardened images
all versions
debian
debian linux
11.0
redhat
enterprise linux
10.0, 6.0, 7.0, 8.0, 9.0

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CVE-2026-21321Shared CWE-190
CVE-2026-24875Shared CWE-190
CVE-2026-40250Shared CWE-190
CVE-2025-61144Same product: Libtiff Libtiff

References