CVE-2026-6104 (GCVE-0-2026-6104)

Vulnerability from cvelistv5 – Published: 2026-05-10 04:35 – Updated: 2026-07-15 00:41
VLAI
Title
Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding
Summary
In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.
Severity
6.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/RE:M/U:Amber
8.2 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-11 13:04 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
PHP Group PHP Affected: 8.4.* , < 8.4.21 (semver)
Affected: 8.5.* , < 8.5.6 (semver)
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Red Hat Red Hat Enterprise Linux 10 Unaffected: 0:8.4.21-1.el10_2 , < * (rpm)
    cpe:/o:redhat:enterprise_linux:10.2
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Red Hat Red Hat Enterprise Linux 10     cpe:/o:redhat:enterprise_linux:10
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Red Hat Red Hat Enterprise Linux 6     cpe:/o:redhat:enterprise_linux:6
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Red Hat Red Hat Enterprise Linux 7     cpe:/o:redhat:enterprise_linux:7
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Red Hat Red Hat Enterprise Linux 8     cpe:/o:redhat:enterprise_linux:8
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Red Hat Red Hat Enterprise Linux 9     cpe:/o:redhat:enterprise_linux:9
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Red Hat Red Hat Hardened Images     cpe:/a:redhat:hummingbird:1
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Date Public
2026-05-07 00:00
Credits
Akshay Jain Ilija Tovilo
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    "redhat_vex": {
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      "current_release_date": "2026-06-30T03:39:47+00:00",
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      "product_status:fixed": "201",
      "product_status:known_not_affected": "253",
      "source": "Red Hat CSAF VEX",
      "status": "final",
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      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6104.json",
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      "cveMetadata": "{\"cveId\": \"CVE-2026-6104\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-15T00:41:42.455Z\", \"dateReserved\": \"2026-04-11T04:15:03.938Z\", \"assignerOrgId\": \"dd77f84a-d19a-4638-8c3d-a322d820ed2b\", \"datePublished\": \"2026-05-10T04:35:17.328Z\", \"assignerShortName\": \"php\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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Taxonomy of the tags.





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

Author Source Type Date Other

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.