CVE-2015-5523

Exp

The ParseValue function in lexer.c in tidy before 4.9.31 allows remote attackers to cause a denial of service (crash) via vectors involving multiple whitespace characters before an empty href, which triggers a large memory allocation.

Published: 2015-08-11 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-5523 is rated High Exploit Risk (62.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.84%). 3 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2015-5523

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2015-5523

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 4.27% 3.84% -0.43%
2 2026-05-13 5.03% 4.27% -0.76%
3 2025-12-28 — 5.03% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-5523

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2015-5523

OS Trackers for CVE-2015-5523

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2015-5523
suse medium CVE-2015-5523 severity moderate: SUSE including 20 source package names (libtidy-0_99-0-1.0.20100204cvs-25.3, libtidy-0_99-0-devel-1.0.20100204cvs-25.3, …), 58 product×package rows across 26 product lines (SUSE Linux Enterprise Desktop 11 SP3, SUSE Linux Enterprise Desktop 11 SP4, … (26 product lines)): Fixed 58. https://www.suse.com/security/cve/CVE-2015-5523/
ubuntu low CVE-2015-5523 low priority: Ubuntu including 1 source packages (tidy), 5 status rows across 5 suites (precise, trusty, upstream, utopic, vivid): released 4, ignored 1. https://ubuntu.com/security/CVE-2015-5523

Affected software / configurations for CVE-2015-5523

Vendor Product Version Raw CPE
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 15.04 cpe:2.3:o:canonical:ubuntu_linux:15.04:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
apple iphone_os <= 8.2 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple mac_os_x <= 10.6.8 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
apple watchos <= 1.0.1 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
htacg tidy <= 4.9.30 cpe:2.3:a:htacg:tidy:*:*:*:*:*:*:*:*

References for CVE-2015-5523

URL Tags
http://lists.apple.com/archives/security-announce/2015/Sep/msg00001.html Mailing List Third Party Advisory
http://lists.apple.com/archives/security-announce/2015/Sep/msg00005.html Mailing List Third Party Advisory
http://lists.apple.com/archives/security-announce/2015/Sep/msg00008.html Mailing List Third Party Advisory
http://www.debian.org/security/2015/dsa-3309 Third Party Advisory
http://www.openwall.com/lists/oss-security/2015/06/04/2 Exploit
http://www.openwall.com/lists/oss-security/2015/07/13/7 Exploit
http://www.openwall.com/lists/oss-security/2015/07/15/3
http://www.securityfocus.com/bid/75037
http://www.securitytracker.com/id/1033703
http://www.ubuntu.com/usn/USN-2695-1 Third Party Advisory
https://github.com/htacg/tidy-html5/issues/217#issuecomment-108565501 Exploit
https://support.apple.com/HT205212 Third Party Advisory
https://support.apple.com/HT205213 Third Party Advisory
https://support.apple.com/HT205267 Third Party Advisory
cvelogic Threat Intelligence