CVE-2015-5523

MEDIUMCVSS v2 · 4.34.3—
EchelonGraph scoreLOW confidence

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 4.3 — v2 rates that MEDIUM (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:M/Au:N/C:N/I:N/A:P. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 3.8% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.

Sources: epss, nvd_v2
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 4%CVSS v2: 4.3Exploit: None knownExposed: 0

A fix is available — apply it.

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.

CVSS v2.0 (legacy)
4.3MEDIUMNVD never assigned a CVSS v3 rating to this CVE
EG Score
4.3(low)
EG Risk
25(Track)
EG Risk 25/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation4% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
4%
EPSS %ILE
89%
KEV
Not listed

Published

August 11, 2015

Last Modified

May 6, 2026

References (28)

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibtidy-0.99-0 (20091223cvs-1ubuntu2.1) @ precise2026-05-23ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:6.0(1)
PackageVulnerable rangeFixed inDependents
tidy20091223cvs-120091223cvs-1+deb6u1—
Debian:7(1)
PackageVulnerable rangeFixed inDependents
tidy20091223cvs-1.220091223cvs-1.2+deb7u1—
Debian:8(1)
PackageVulnerable rangeFixed inDependents
tidy20091223cvs-1.420091223cvs-1.4+deb8u1—

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 7× in last 7d / 26× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 114 total refreshes for this CVE.

  1. 2026-08-21 23:44 UTCEPSS rescore
  2. 2026-08-20 22:50 UTCEPSS rescore
  3. 2026-08-19 16:59 UTCEPSS rescore
  4. 2026-08-18 13:43 UTCEPSS rescore
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  11. 2026-08-08 16:32 UTCEPSS rescore
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  18. 2026-07-30 01:26 UTCEPSS rescore
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  20. 2026-07-28 15:31 UTCEPSS rescore
  21. 2026-07-26 13:54 UTCEG score recompute▲ 4.30
  22. 2026-07-25 14:13 UTCEPSS rescore
  23. 2026-07-24 14:13 UTCEPSS rescore
  24. 2026-07-23 14:14 UTCEPSS rescore
  25. 2026-07-23 01:18 UTCEG score recompute
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  1. 2026-07-23 00:20 UTCEG score recompute
  2. 2026-07-22 21:59 UTCEG score recompute
  3. 2026-07-22 14:04 UTCEPSS rescore
  4. 2026-07-21 15:21 UTCEPSS rescore
  5. 2026-07-21 15:21 UTCEPSS rescore
  6. 2026-07-20 17:03 UTCEPSS rescore
  7. 2026-07-19 14:27 UTCEPSS rescore
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  11. 2026-07-18 10:00 UTCEPSS rescore
  12. 2026-07-16 16:59 UTCEPSS rescore
  13. 2026-07-15 16:54 UTCEPSS rescore
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  15. 2026-07-15 01:56 UTCEPSS rescore
  16. 2026-07-13 22:26 UTCEPSS rescore
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  18. 2026-07-12 05:42 UTCEPSS rescore
  19. 2026-07-11 08:23 UTCEPSS rescore
  20. 2026-07-09 19:05 UTCEPSS rescore
  21. 2026-07-09 19:05 UTCEPSS rescore
  22. 2026-07-08 15:10 UTCEPSS rescore
  23. 2026-07-07 13:42 UTCEPSS rescore
  24. 2026-07-07 13:42 UTCEPSS rescore
  25. 2026-07-06 16:24 UTCEPSS rescore
  26. 2026-07-06 02:20 UTCEPSS rescore
  27. 2026-07-05 02:26 UTCEPSS rescore
  28. 2026-07-04 06:28 UTCEPSS rescore
  29. 2026-07-01 15:02 UTCEPSS rescore
  30. 2026-06-30 23:19 UTCEPSS rescore
  31. 2026-06-30 23:19 UTCEPSS rescore
  32. 2026-06-28 04:53 UTCEPSS rescore
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  34. 2026-06-25 13:47 UTCEPSS rescore
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  36. 2026-06-24 14:02 UTCEPSS rescore
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  38. 2026-06-23 21:30 UTCEPSS rescore
  39. 2026-06-21 14:54 UTCEPSS rescore
  40. 2026-06-21 14:54 UTCEPSS rescore
  41. 2026-06-21 01:57 UTCEPSS rescore
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  43. 2026-06-19 19:23 UTCEPSS rescore
  44. 2026-06-19 19:23 UTCEPSS rescore
  45. 2026-06-18 17:50 UTCEPSS rescore
  46. 2026-06-17 17:50 UTCEPSS rescore
  47. 2026-06-17 17:49 UTCEPSS rescore
  48. 2026-06-16 17:50 UTCEPSS rescore
  49. 2026-06-16 17:50 UTCEPSS rescore
  50. 2026-06-15 17:45 UTCEPSS rescore
  51. 2026-06-13 22:57 UTCEPSS rescore
  52. 2026-06-12 23:09 UTCEPSS rescore
  53. 2026-06-12 23:09 UTCEPSS rescore
  54. 2026-06-11 13:57 UTCEPSS rescore
  55. 2026-06-11 13:57 UTCEPSS rescore
  56. 2026-06-10 22:15 UTCEPSS rescore
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  58. 2026-06-06 13:45 UTCEPSS rescore
  59. 2026-06-05 22:44 UTCEPSS rescore
  60. 2026-06-05 06:08 UTCEPSS rescore
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  62. 2026-06-04 13:10 UTCEPSS rescore
  63. 2026-06-04 13:10 UTCEPSS rescore
  64. 2026-06-02 20:10 UTCEPSS rescore
  65. 2026-06-01 13:49 UTCEPSS rescore
  66. 2026-06-01 13:49 UTCEPSS rescore
  67. 2026-05-31 22:28 UTCEPSS rescore
  68. 2026-05-31 22:28 UTCEPSS rescore
  69. 2026-05-31 00:14 UTCEPSS rescore
  70. 2026-05-29 13:41 UTCEPSS rescore
  71. 2026-05-28 13:42 UTCEPSS rescore
  72. 2026-05-28 13:42 UTCEPSS rescore
  73. 2026-05-27 13:38 UTCEPSS rescore
  74. 2026-05-27 13:38 UTCEPSS rescore
  75. 2026-05-26 07:16 UTCEPSS rescore

Related CVEs(same vendor)

Frequently asked(4)

What is CVE-2015-5523?
CVE-2015-5523 is a medium vulnerability published on August 11, 2015. 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.
When was CVE-2015-5523 disclosed?
CVE-2015-5523 was first published in the National Vulnerability Database on August 11, 2015, with the most recent update on May 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2015-5523 actively exploited?
CVE-2015-5523 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 4% probability of exploitation in the next 30 days, which ranks it in the top 10.7% of all scored CVEs.
How do I remediate CVE-2015-5523?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2015-5523, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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