CVE-2026-42310

Impact

An attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive.

Patches

Patched version: 12.2.0.

PdfParser (introduced in Pillow 4.2.0) follows Prev pointers in PDF trailers to read cross-reference sections. If a trailer's Prev pointer references an offset that has already been processed — either pointing to itself or forming a longer cycle — the parser enters an infinite loop. Pillow now tracks previously processed trailer offsets and raises an error if a cycle is detected.

Workarounds

Use any version but the affected versions: >= 4.2.0, < 12.2.0

Resources

• Fix: https://github.com/python-pillow/Pillow/pull/9519

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

Pillow is a Python imaging library. Prior to version 12.2.0, if a font advances for each glyph by an exceeding large amount, when Pillow keeps track of the current position, it may lead to an integer overflow. This issue has been patched in version 12.2.0.(CVE-2026-42308)

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.(CVE-2026-42310)

Pillow is a Python imaging library. From version 10.3.0 to before version 12.2.0, processing a malicious PSD file could lead to memory corruption, potentially resulting in a crash or arbitrary code execution. This issue has been patched in version 12.2.0.(CVE-2026-42311)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

Pillow is a Python imaging library. Prior to version 12.2.0, if a font advances for each glyph by an exceeding large amount, when Pillow keeps track of the current position, it may lead to an integer overflow. This issue has been patched in version 12.2.0.(CVE-2026-42308)

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.(CVE-2026-42310)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

Pillow is a Python imaging library. Prior to version 12.2.0, if a font advances for each glyph by an exceeding large amount, when Pillow keeps track of the current position, it may lead to an integer overflow. This issue has been patched in version 12.2.0.(CVE-2026-42308)

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.(CVE-2026-42310)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

Pillow is a Python imaging library. Prior to version 12.2.0, if a font advances for each glyph by an exceeding large amount, when Pillow keeps track of the current position, it may lead to an integer overflow. This issue has been patched in version 12.2.0.(CVE-2026-42308)

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.(CVE-2026-42310)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

Pillow is a Python imaging library. Prior to version 12.2.0, if a font advances for each glyph by an exceeding large amount, when Pillow keeps track of the current position, it may lead to an integer overflow. This issue has been patched in version 12.2.0.(CVE-2026-42308)

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.(CVE-2026-42310)

Impact

An attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive.

Patches

Patched version: 12.2.0.

PdfParser (introduced in Pillow 4.2.0) follows Prev pointers in PDF trailers to read cross-reference sections. If a trailer's Prev pointer references an offset that has already been processed — either pointing to itself or forming a longer cycle — the parser enters an infinite loop. Pillow now tracks previously processed trailer offsets and raises an error if a cycle is detected.

Workarounds

Use any version but the affected versions: >= 4.2.0, < 12.2.0

Resources

• Fix: https://github.com/python-pillow/Pillow/pull/9519

Root has patched CVE-2026-42310 in the pillow package for Root:PyPI. Multiple fixed versions available.

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.

TuxCare rebuilt pillow to address 1 CVE. Fixed in 9.5.0.post5+tuxcare.

TuxCare rebuilt pillow to address 1 CVE. Fixed in 10.4.0.post7+tuxcare.

TuxCare rebuilt pillow to address 1 CVE. Fixed in 11.2.1.post6+tuxcare.

TuxCare rebuilt pillow to address 1 CVE. Fixed in 9.4.0.post7+tuxcare.

TuxCare rebuilt pillow to address 1 CVE. Fixed in 8.4.0.post7+tuxcare.

TuxCare rebuilt pillow to address 14 CVEs. Fixed in 11.3.0.post5+tuxcare.

Integer overflow when processing fonts. (CVE-2026-42308) PDF Parsing Trailer Infinite Loop (DoS). (CVE-2026-42310)

This update for python-Pillow fixes the following issues

• CVE-2026-42308: integer overflow in font processing can lead to denial of service (bsc#1265359).
• CVE-2026-42309: heap buffer overflow when processing nested list coordinates (bsc#1265153).
• CVE-2026-42310: infinite loop and resource exhaustion when processing specially crafted PDFs (bsc#1265154).

This update for python-Pillow fixes the following issue

• CVE-2026-42310: infinite loop and resource exhaustion when processing specially crafted PDFs (bsc#1265154).

This update for python-Pillow fixes the following issues

• CVE-2026-42308: integer overflow in font processing can lead to denial of service (bsc#1265359).
• CVE-2026-42309: heap buffer overflow when processing nested list coordinates (bsc#1265153).
• CVE-2026-42310: infinite loop and resource exhaustion when processing specially crafted PDFs (bsc#1265154).

This update for python-Pillow fixes the following issues

• CVE-2026-42308: integer overflow in font processing can lead to denial of service (bsc#1265359).
• CVE-2026-42310: infinite loop and resource exhaustion when processing specially crafted PDFs (bsc#1265154).

It was discovered that Pillow incorrectly handled large glyph advance values in fonts. An attacker could possibly use this issue to cause Pillow to crash, resulting in a denial of service. (CVE-2026-42308)

It was discovered that Pillow incorrectly handled nested coordinate lists in certain APIs. An attacker could possibly use this issue to cause Pillow to crash, resulting in a denial of service. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-42309)

It was discovered that Pillow incorrectly handled certain malformed PDF files. An attacker could possibly use this issue to cause Pillow to use excessive resources, leading to a denial of service. (CVE-2026-42310)

It was discovered that Pillow incorrectly handled certain malformed PSD files. An attacker could possibly use this issue to cause Pillow to crash, resulting in a denial of service, or to execute arbitrary code. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-42311)