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Resource Allocation Without LimitsWeakness · CWE-770

CVE-2026-46599

HIGH · 7.5 CVSS v3.1 Published 2026-05-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The TIFF decoder does not place a limit on the size of PackBits-compressed data. A maliciously-crafted image can exploit this to cause a small image (both in terms of pixel width/height and encoded size) to make the decoder decode large amounts of compressed data.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The TIFF decoder lacks bounds checking on PackBits-compressed data, allowing a small compressed image to expand to arbitrarily large sizes during decoding. This is a classic decompression bomb vulnerability where the expansion ratio between compressed and uncompressed data is not validated, enabling denial of service through excessive memory allocation.

MitigationImplement a size limit check that validates the expected uncompressed size against the actual image dimensions before decoding, rejecting PackBits data that would expand beyond reasonable bounds relative to the image dimensions.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify TIFF-processing software on the system
    Search for installed libraries or applications that handle TIFF images, such as libtiff, ImageMagick, GraphicsMagick, or other TIFF-enabled image tools. Use package managers (dpkg, rpm, brew) or file system searches for TIFF-related binaries and libraries.
    Affected if TIFF processing software with PackBits decoding capability is present without documented size-limit enforcement on decompressed data.
  2. Confirm PackBits compression support is enabled
    Examine the TIFF software configuration or documentation to verify that PackBits compression (compression type 32773) is listed as a supported or enabled decompression method. Check command-line tools for compression-related flags or API documentation for codec availability.
    Affected if PackBits compression decoding is available and no explicit size-limiting validation is documented in the decoder.
  3. Verify bounds checking on decoded PackBits output
    Inspect the TIFF decoder source code, if accessible, for size validation before or during PackBits decompression. Look for checks that validate decompressed size against available buffer space or memory limits before allocation. If source is unavailable, check vendor security advisories or release notes for mention of PackBits size-limit fixes.
    Affected if The decoder lacks explicit size validation that prevents allocation of unbounded output buffers during PackBits decompression.
  4. Test for decompression bomb resistance (optional validation)
    If permitted in your environment, process a known-small PackBits-compressed TIFF file (e.g., a few hundred bytes) that expands to a large size (>100MB) and observe whether the decoder enforces a size limit, rejects the file, or allows unbounded expansion.
    Affected if The decoder allows processing without rejecting files that expand beyond reasonable memory bounds.

The environment is affected if any TIFF-processing software with PackBits decoding is present and does not implement explicit size limits on decompressed PackBits data, allowing potential memory exhaustion from specially crafted images.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement a size limit check that validates the expected uncompressed size against the actual image dimensions before decoding, rejecting PackBits data that would expand beyond reasonable bounds relative to the image dimensions.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-46599 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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