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CVE-2026-42504 (GCVE-0-2026-42504)

Vulnerability from cvelistv5 – Published: 2026-06-02 22:01 – Updated: 2026-09-02 19:37
VLAI
Title
Quadratic complexity in WordDecoder.DecodeHeader in mime
Summary
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-03 14:05 UTC
CWE
  • CWE-407 - Inefficient Algorithmic Complexity
Assigner
References
Impacted products
Vendor Product Version CPE status
Go standard library mime Affected: 0 , < 1.25.11 (semver)
Affected: 1.26.0-0 , < 1.26.4 (semver)
guessed Create a notification for this product.
Credits
p4p3r (https://hackerone.com/p4p3r_hak)
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.