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Fencer Intel
critical 9.8

CVE-2010-1866 in the critical feed json

The dechunk filter in PHP 5.3 through 5.3.2, when decoding an HTTP chunked encoding stream, allows context-dependent attackers to cause a d…

published 16y ago modified 4mo ago also EUVD-2010-1886

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
6.7%
EPSS 6.7% chance of exploitation in 30 days, percentile 93%
public exploits
1
Exploit-DB

Summary

The dechunk filter in PHP 5.3 through 5.3.2, when decoding an HTTP chunked encoding stream, allows context-dependent attackers to cause a denial of service (crash) and possibly trigger memory corruption via a negative chunk size, which bypasses a signed comparison, related to an integer overflow in the chunk size decoder.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2010-1866 updated cvss 5.1

php: dechunk filter integer signedness error causing buffer overflow (MOPS-2010-003)

  • Red Hat Enterprise Linux 4 php Red Hat Enterprise Linux 5 php Red Hat Enterprise Linux 6 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +20 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. First public exploit (EDB-33920)
  2. Published

Exploit prediction

6.72% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-33920 PHP 5.3 - 'PHP_dechunk()' HTTP Chunked Encoding Integer Overflow remote, 2010-05-02
  • php-security.org http://php-security.org/2010/05/02/mops-2010-003-php-dechunk-filter-signed-comparison-vulnerability/index.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.