CVE-2026-17544

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 63% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this weekElevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

Attacker-provided inputs to bccomp() could lead to an out-of-bounds write with stack and heap corruption in PHP versions from 8.4.* before 8.4.24 and from 8.5.* before 8.5.9.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Track)
EG Risk 75/100SSVC: 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%
Exploitation40% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

July 30, 2026

Last Modified

August 5, 2026

Advisory Details (1)

Auto-updated Sep 16, 2026
Patch available. Sources: github.
github Patch Available

Out-of-bounds write in bccomp() via crafted operand and scale · Advisory · php/php-src · GitHub

https://github.com/php/php-src/security/advisories/GHSA-x692-q9x7-8c3f

Vendor Advisories for CVE-2026-17544(2)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuphp8.5-zip (8.5.4-0ubuntu1.3) @ resolute2026-09-20ubuntu
redhatphp8.4-0:8.4.24-1.el10_22026-08-19redhat
redhatphp-main-8.5.9-1.hum12026-07-28redhat

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
php7.47.4.21-1+deb11u1 ... 7.4.33-1+deb11u9 (15 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
php8.28.2.10-1 ... 8.2.7-1~deb12u1 (28 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
php8.48.4.11-1 ... 8.4.23-1~deb13u1 (9 versions)8.4.24-1~deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
php8.48.4.11-1 ... 8.4.24-1~deb13u1 (10 versions)8.4.24-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 32× in last 7d / 161× 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 311 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCBoreas37/CVE-2026-17544-PoC
    First seen Aug 12, 2026

    CVE-2026-17544 — PHP bcmath bccomp() OOB write (stack smashing). Verified: crash on 8.4.23/8.5.8, fixed in 8.4.24. GHSA-x692-q9x7-8c3f

    Open source ↗

Related CVEs(same vendor + same CWE)

Same vendor

2 shown

redhat:RHSA-2026:47200

Frequently asked(5)

What is CVE-2026-17544?
CVE-2026-17544 is a critical vulnerability published on July 30, 2026. Attacker-provided inputs to bccomp() could lead to an out-of-bounds write with stack and heap corruption in PHP versions from 8.4. before 8.4.24 and from 8.5. before 8.5.9.
When was CVE-2026-17544 disclosed?
CVE-2026-17544 was first published in the National Vulnerability Database on July 30, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-17544 actively exploited?
CVE-2026-17544 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 63.5% of all scored CVEs.
What is the CVSS score of CVE-2026-17544?
CVE-2026-17544 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-17544?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-17544, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-17544

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