CVE-2010-1866

Name: CVE-2010-1866
Creator: NVD / NIST
Published: 2010-05-07T23:00:01.86+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 6.72%

Last modified Jun 16, 2026

CVE-2010-1866 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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.. EPSS estimates a 6.72% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

6.72%

93.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-190

Affected Software

Vendor	Product	Versions	Update
Php	Php	>= 5.3.0, <= 5.3.2	—
Opensuse	Opensuse	11.1	—
Opensuse	Opensuse	11.2	—
Opensuse	Opensuse	11.3	—
Suse	Linux Enterprise	10.0	Sp3
Suse	Linux Enterprise	11.0	—

References

http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.htmlMailing List
http://php-security.org/2010/05/02/mops-2010-003-php-dechunk-filter-signed-comparison-vulnerability/index.htmlBroken Link, Exploit
http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.htmlMailing List
http://php-security.org/2010/05/02/mops-2010-003-php-dechunk-filter-signed-comparison-vulnerability/index.htmlBroken Link, Exploit

Timeline

Published: May 7, 2010
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2010-1866?

How severe is CVE-2010-1866?

CVE-2010-1866 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 6.72% probability of exploitation in the next 30 days.

How do I fix CVE-2010-1866?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2010-1866?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST