CVE-2025-15646

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-01. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

HTML::Gumbo versions before 0.19 for Perl disclose heap memory via type confusion.

Support for the element was added to libgumbo 0.10.0 in 2015, but the walk_tree function in lib/HTML/Gumbo.xs was not updated to support it. The element was treated as a text-node, where strlen() over-reads the heap block that the pointer addresses.

Any caller that runs parse() with the default format => 'string', or with format => 'tree', on input containing a element serializes the over-read bytes into the returned result, disclosing bounded heap contents. format => 'callback' reaches a croak on the unhandled node type and is unaffected.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
49%
KEV
Not listed

Published

July 1, 2026

Last Modified

July 2, 2026

Advisory Details (4)

Auto-updated Aug 22, 2026
Patch available.
generic

oss-security - CVE-2025-15646: HTML::Gumbo versions before 0.19 for Perl disclose heap memory via type confusion

http://www.openwall.com/lists/oss-security/2026/07/01/7
generic

Client Challenge

https://metacpan.org/release/BPS/HTML-Gumbo-0.19/changes
generic
https://github.com/bestpractical/HTML-Gumbo/commit/15c0598909d4a64f47ef0a1abc5051f4e113c186.patch
generic Patch Available

#1104789 - libhtml-gumbo-perl: erratic behavior on the unsupported template HTML element - GUMBO_NODE_TEMPLATE node type (CVE-2025-15646) - Debian Bug report logs

https://bugs.debian.org/1104789

Vendor Advisories for CVE-2025-15646(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
libhtml-gumbo-perl0.18-2 ... 0.20-1 (6 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
libhtml-gumbo-perl0.18-30.18-3+deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
libhtml-gumbo-perl—0.18-5—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libhtml-gumbo-perl—0.18-5—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 43× in last 7d / 225× 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 350 total refreshes for this CVE.

  1. 2026-08-25 13:47 UTCEPSS rescore
  2. 2026-08-25 04:45 UTCGHSA enrichment
  3. 2026-08-25 00:53 UTCGHSA enrichment
  4. 2026-08-24 21:02 UTCGHSA enrichment
  5. 2026-08-24 14:46 UTCEG score recompute
  6. 2026-08-24 14:46 UTCGHSA enrichment
  7. 2026-08-24 14:15 UTCEPSS rescore
  8. 2026-08-24 10:54 UTCEG score recompute
  9. 2026-08-24 10:54 UTCGHSA enrichment
  10. 2026-08-24 04:11 UTCGHSA enrichment
  11. 2026-08-23 23:07 UTCGHSA enrichment
  12. 2026-08-23 19:15 UTCGHSA enrichment
  13. 2026-08-23 15:22 UTCGHSA enrichment
  14. 2026-08-23 11:30 UTCGHSA enrichment
  15. 2026-08-23 07:38 UTCGHSA enrichment
  16. 2026-08-23 03:47 UTCEG score recompute
  17. 2026-08-23 03:47 UTCGHSA enrichment
  18. 2026-08-23 00:18 UTCEPSS rescore
  19. 2026-08-22 23:55 UTCGHSA enrichment
  20. 2026-08-22 20:03 UTCGHSA enrichment
  21. 2026-08-22 15:05 UTCGHSA enrichment
  22. 2026-08-22 11:12 UTCGHSA enrichment
  23. 2026-08-22 07:20 UTCGHSA enrichment
  24. 2026-08-22 01:02 UTCEG score recompute
  25. 2026-08-22 01:02 UTCGHSA enrichment
Show 75 more
  1. 2026-08-21 23:48 UTCEPSS rescore
  2. 2026-08-21 21:09 UTCGHSA enrichment
  3. 2026-08-21 17:17 UTCGHSA enrichment
  4. 2026-08-21 12:22 UTCGHSA enrichment
  5. 2026-08-21 08:25 UTCGHSA enrichment
  6. 2026-08-21 04:33 UTCGHSA enrichment
  7. 2026-08-21 00:01 UTCEG score recompute
  8. 2026-08-21 00:01 UTCGHSA enrichment
  9. 2026-08-20 22:54 UTCEPSS rescore
  10. 2026-08-20 20:09 UTCGHSA enrichment
  11. 2026-08-20 16:18 UTCGHSA enrichment
  12. 2026-08-20 12:27 UTCGHSA enrichment
  13. 2026-08-20 08:36 UTCGHSA enrichment
  14. 2026-08-20 04:44 UTCEG score recompute
  15. 2026-08-20 04:44 UTCGHSA enrichment
  16. 2026-08-19 17:02 UTCEPSS rescore
  17. 2026-08-19 16:29 UTCGHSA enrichment
  18. 2026-08-19 12:33 UTCGHSA enrichment
  19. 2026-08-19 08:42 UTCGHSA enrichment
  20. 2026-08-19 04:50 UTCGHSA enrichment
  21. 2026-08-19 00:59 UTCGHSA enrichment
  22. 2026-08-18 21:00 UTCEG score recompute
  23. 2026-08-18 21:00 UTCGHSA enrichment
  24. 2026-08-18 13:47 UTCEPSS rescore
  25. 2026-08-18 04:50 UTCGHSA enrichment
  26. 2026-08-17 23:32 UTCGHSA enrichment
  27. 2026-08-17 16:50 UTCEG score recompute
  28. 2026-08-17 16:50 UTCGHSA enrichment
  29. 2026-08-17 13:46 UTCEPSS rescore
  30. 2026-08-17 12:26 UTCGHSA enrichment
  31. 2026-08-17 08:11 UTCGHSA enrichment
  32. 2026-08-17 04:20 UTCGHSA enrichment
  33. 2026-08-17 00:28 UTCGHSA enrichment
  34. 2026-08-16 20:36 UTCGHSA enrichment
  35. 2026-08-16 16:44 UTCEG score recompute
  36. 2026-08-16 16:44 UTCGHSA enrichment
  37. 2026-08-16 14:55 UTCEPSS rescore
  38. 2026-08-16 12:53 UTCGHSA enrichment
  39. 2026-08-16 09:01 UTCGHSA enrichment
  40. 2026-08-16 05:10 UTCEG score recompute
  41. 2026-08-16 05:10 UTCGHSA enrichment
  42. 2026-08-16 02:13 UTCEPSS rescore
  43. 2026-08-16 02:13 UTCEPSS rescore
  44. 2026-08-16 01:18 UTCGHSA enrichment
  45. 2026-08-15 21:27 UTCGHSA enrichment
  46. 2026-08-15 17:35 UTCGHSA enrichment
  47. 2026-08-15 13:43 UTCGHSA enrichment
  48. 2026-08-15 09:49 UTCGHSA enrichment
  49. 2026-08-15 05:58 UTCGHSA enrichment
  50. 2026-08-15 02:06 UTCEG score recompute
  51. 2026-08-15 02:06 UTCGHSA enrichment
  52. 2026-08-15 01:29 UTCEPSS rescore
  53. 2026-08-14 22:15 UTCGHSA enrichment
  54. 2026-08-14 18:24 UTCGHSA enrichment
  55. 2026-08-14 14:32 UTCGHSA enrichment
  56. 2026-08-14 10:41 UTCGHSA enrichment
  57. 2026-08-14 06:50 UTCGHSA enrichment
  58. 2026-08-14 02:58 UTCGHSA enrichment
  59. 2026-08-13 23:07 UTCEG score recompute
  60. 2026-08-13 23:07 UTCGHSA enrichment
  61. 2026-08-13 21:59 UTCEPSS rescore
  62. 2026-08-13 19:14 UTCGHSA enrichment
  63. 2026-08-13 15:22 UTCGHSA enrichment
  64. 2026-08-13 11:30 UTCGHSA enrichment
  65. 2026-08-13 07:39 UTCGHSA enrichment
  66. 2026-08-13 03:13 UTCGHSA enrichment
  67. 2026-08-12 23:22 UTCGHSA enrichment
  68. 2026-08-12 19:31 UTCGHSA enrichment
  69. 2026-08-12 15:40 UTCEG score recompute
  70. 2026-08-12 15:40 UTCGHSA enrichment
  71. 2026-08-12 13:49 UTCEPSS rescore
  72. 2026-08-12 11:28 UTCGHSA enrichment
  73. 2026-08-12 07:36 UTCGHSA enrichment
  74. 2026-08-12 03:45 UTCGHSA enrichment
  75. 2026-08-11 23:53 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2025-15646?
CVE-2025-15646 is a critical vulnerability published on July 1, 2026. HTML::Gumbo versions before 0.19 for Perl disclose heap memory via type confusion. Support for the <template> element was added to libgumbo 0.10.0 in 2015, but the walk_tree function in lib/HTML/Gumbo.xs was not updated to support it. The element was treated as a text-node, where strlen()…
When was CVE-2025-15646 disclosed?
CVE-2025-15646 was first published in the National Vulnerability Database on July 1, 2026, with the most recent update on July 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-15646 actively exploited?
CVE-2025-15646 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 50.7% of all scored CVEs.
What is the CVSS score of CVE-2025-15646?
CVE-2025-15646 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2025-15646?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-15646, 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.

Dependency Blast Radius

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