Public proof of concept

CVE-2010-1866

A public proof of concept exists; no exploitation attested.

Published2010-05-07
WeaknessCWE-190

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC

2010-05-0723:00CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2010-1866?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2010-1866?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Opensuse

Branch	Affected	Fixed in	Source
11.1	= 11.1	no fix published	NVD
11.2	= 11.2	no fix published	NVD
11.3	= 11.3	no fix published	NVD

Suse linux enterprise

Branch	Affected	Fixed in	Source
10.0	= 10.0	no fix published	NVD
11.0	= 11.0	no fix published	NVD

PHP

Branch	Affected	Fixed in	Source
5.3	≥ 5.3.0, ≤ 5.3.2	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

No fix published by the sources we read yet. NVD record

Detection

read 2026-10-23 19:23 UTC

Nuclei template: none so far
Exploit-DB: EDB-33920
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-190read 2026-10-23
FIRST EPSSEPSS score6.7 %2026-10-22
Exploit-DBdetectionread 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2010-05-07
Last Modified: 2026-06-16
NVD status: Modified

Frequently asked questions

What is CVE-2010-1866?

Is CVE-2010-1866 actively exploited?

Active exploitation of CVE-2010-1866 has not been confirmed. Its EPSS score was 6.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2010-1866?

CVE-2010-1866 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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