VulnerabilityPublished 13 Nov 2026

CVE-2026-128066: Pillow · Memory DoS in TIFF and EXIF IFD parsing via overlapping tag data

Affects aiderSource GCVE Database

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Authoritative record:CVE-2026-128066· High 8.7

Not known to be exploited · CVSS 8.7 High.

Data as of 13 Nov 2026, 21:33 UTC

CVSS 4.0 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 4.0	8.7

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: High
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Homebrewaider`pkg:brew/aider`Other threats	Affected >=0.86.1_1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until a fix is available, avoid processing untrusted TIFF, JPEG, PNG, WebP, and MPO images with Pillow or implement external limits on memory usage or file size. Monitor vendor channels for updates.

Description

A memory denial-of-service vulnerability exists in Pillow's TIFF and EXIF IFD parsing due to overlapping tag data. Crafted image files can cause Pillow to consume thousands of times their size in memory during parsing, leading to process crashes or stalls. This affects TIFF, JPEG, PNG, WebP, and MPO images. The flaw has existed since Pillow 1.0 and involves unbounded memory allocation when reading tag data offsets that overlap or cover the entire file.

Impact

The impact is denial of service through excessive memory consumption, which can crash or stall processes handling image files. A small crafted TIFF (144 KB) can cause Pillow to allocate over 1.6 GiB of memory, while larger files can request tens of gigabytes, typically resulting in process termination by the operating system. This affects any system that processes untrusted images with Pillow, potentially allowing attackers to disrupt services or applications by submitting malicious images.

Summary

The vulnerability (CVE-2026-128066) resides in the ImageFileDirectory_v2.load() function of Pillow's TiffImagePlugin.py, where each IFD entry's value is read into memory without limiting the total amount or preventing multiple entries from referencing the same large data region. An attacker can craft an image with many entries pointing to overlapping or identical large data blocks, causing memory usage to grow quadratically with file size. This leads to excessive memory consumption during Image.open() or getexif() calls on TIFF, JPEG, PNG, WebP, and MPO images. The decompression bomb check does not trigger because the image dimensions are minimal (e.g., 1×1), so no warnings occur. The issue has been present since Pillow 1.0 and affects all releases up to the analyzed commit. There is no memory corruption, only denial of service via memory exhaustion.

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What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Nov 2026, 21:33 UTC

Technical details

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