CVE-2026-71981

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-01. a secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.8Exploit: None knownExposed: 0

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

Cypht before 2.12.2 contains a PHP object injection vulnerability that allows authenticated attackers to execute arbitrary operating system commands by supplying a crafted PHP object graph in the back_query GET parameter of the logout handler. Attackers can pass a base64-encoded serialized payload through this parameter, which is decoded and passed directly to unserialize() without an allow-list, signature check, or type restriction, enabling gadget-chain exploitation to achieve remote code execution as the web server process.

CVSS v3
8.8
EG Score
8.8(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 8, 2026

Advisory Details (4)

Auto-updated Sep 1, 2026
Patch available. Sources: github_release, github_pr, github_commit.
generic

Cypht < 2.12.2 PHP Object Injection RCE via back_query Parameter | Advisories | VulnCheck

https://www.vulncheck.com/advisories/cypht-php-object-injection-rce-via-back-query-parameter
github_commit

commit e4aa2f34e33f (cypht-org/cypht)

Fix landed in cypht-org/cypht commit e4aa2f34e33f — awaiting tagged release

https://github.com/cypht-org/cypht/commit/e4aa2f34e33f9328e8c93514cc3966fc3d99925e
github_pr

fix(module/core): stop deserializing logout back_query

Fix merged in cypht-org/cypht PR #2073 on 2026-08-28 — awaiting tagged release

https://github.com/cypht-org/cypht/pull/2073
github_release Patch Available

v2.12.2

Patch available: cypht-org/cypht v2.12.2

https://github.com/cypht-org/cypht/releases/tag/v2.12.2

Vendor Advisories for CVE-2026-71981(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 26× in last 7d / 76× 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.

  1. 2026-09-21 06:30 UTCEG score recompute
  2. 2026-09-21 06:30 UTCGHSA enrichment
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-20 18:52 UTCGHSA enrichment
  5. 2026-09-20 07:14 UTCGHSA enrichment
  6. 2026-09-19 19:20 UTCEG score recompute
  7. 2026-09-19 19:20 UTCGHSA enrichment
  8. 2026-09-19 07:39 UTCGHSA enrichment
  9. 2026-09-18 20:01 UTCEG score recompute
  10. 2026-09-18 20:01 UTCGHSA enrichment
  11. 2026-09-18 19:28 UTCEPSS rescore
  12. 2026-09-18 08:22 UTCGHSA enrichment
  13. 2026-09-17 20:40 UTCEG score recompute
  14. 2026-09-17 20:40 UTCGHSA enrichment
  15. 2026-09-17 09:00 UTCGHSA enrichment
  16. 2026-09-16 21:22 UTCEG score recompute
  17. 2026-09-16 21:22 UTCGHSA enrichment
  18. 2026-09-16 14:08 UTCEPSS rescore
  19. 2026-09-16 09:05 UTCEG score recompute
  20. 2026-09-16 09:05 UTCGHSA enrichment
  21. 2026-09-16 05:15 UTCEPSS rescore
  22. 2026-09-15 20:54 UTCGHSA enrichment
  23. 2026-09-15 08:59 UTCEG score recompute
  24. 2026-09-15 08:59 UTCGHSA enrichment
  25. 2026-09-15 03:12 UTCEPSS rescore
Show 51 more
  1. 2026-09-14 21:21 UTCGHSA enrichment
  2. 2026-09-14 09:42 UTCGHSA enrichment
  3. 2026-09-13 22:02 UTCEG score recompute
  4. 2026-09-13 22:02 UTCGHSA enrichment
  5. 2026-09-13 10:24 UTCGHSA enrichment
  6. 2026-09-12 22:46 UTCEG score recompute
  7. 2026-09-12 22:46 UTCGHSA enrichment
  8. 2026-09-12 15:02 UTCEPSS rescore
  9. 2026-09-12 11:07 UTCGHSA enrichment
  10. 2026-09-11 23:17 UTCEG score recompute
  11. 2026-09-11 23:17 UTCGHSA enrichment
  12. 2026-09-11 14:53 UTCEPSS rescore
  13. 2026-09-11 10:48 UTCEG score recompute
  14. 2026-09-11 10:48 UTCGHSA enrichment
  15. 2026-09-10 23:09 UTCGHSA enrichment
  16. 2026-09-10 11:30 UTCEG score recompute
  17. 2026-09-10 11:30 UTCGHSA enrichment
  18. 2026-09-10 09:35 UTCEPSS rescore
  19. 2026-09-09 23:35 UTCGHSA enrichment
  20. 2026-09-09 08:28 UTCEG score recompute
  21. 2026-09-09 08:28 UTCGHSA enrichment
  22. 2026-09-08 22:01 UTCEPSS rescore
  23. 2026-09-08 20:50 UTCGHSA enrichment
  24. 2026-09-08 11:22 UTCGHSA enrichment
  25. 2026-09-07 23:45 UTCEG score recompute
  26. 2026-09-07 23:44 UTCGHSA enrichment
  27. 2026-09-07 12:06 UTCGHSA enrichment
  28. 2026-09-07 00:27 UTCEG score recompute
  29. 2026-09-07 00:27 UTCGHSA enrichment
  30. 2026-09-06 13:48 UTCEPSS rescore
  31. 2026-09-06 12:47 UTCGHSA enrichment
  32. 2026-09-06 01:09 UTCEG score recompute
  33. 2026-09-06 01:08 UTCGHSA enrichment
  34. 2026-09-05 13:28 UTCGHSA enrichment
  35. 2026-09-05 01:49 UTCGHSA enrichment
  36. 2026-09-04 14:10 UTCEG score recompute
  37. 2026-09-04 14:10 UTCGHSA enrichment
  38. 2026-09-04 05:07 UTCEPSS rescore
  39. 2026-09-04 02:31 UTCGHSA enrichment
  40. 2026-09-03 14:51 UTCGHSA enrichment
  41. 2026-09-03 03:12 UTCGHSA enrichment
  42. 2026-09-02 15:31 UTCEG score recompute
  43. 2026-09-02 15:31 UTCGHSA enrichment
  44. 2026-09-02 15:01 UTCEG score recompute
  45. 2026-09-02 15:00 UTCGHSA enrichment
  46. 2026-09-02 14:12 UTCEPSS rescore
  47. 2026-09-02 09:04 UTCEG score recompute
  48. 2026-09-02 09:04 UTCGHSA enrichment
  49. 2026-09-01 21:26 UTCEG score recompute
  50. 2026-09-01 20:48 UTCEG score recompute
  51. 2026-09-01 20:47 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-71981?
CVE-2026-71981 is a high vulnerability published on September 1, 2026. Cypht before 2.12.2 contains a PHP object injection vulnerability that allows authenticated attackers to execute arbitrary operating system commands by supplying a crafted PHP object graph in the back_query GET parameter of the logout handler. Attackers can pass a base64-encoded serialized payload…
When was CVE-2026-71981 disclosed?
CVE-2026-71981 was first published in the National Vulnerability Database on September 1, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-71981 actively exploited?
CVE-2026-71981 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 54.3% of all scored CVEs.
What is the CVSS score of CVE-2026-71981?
CVE-2026-71981 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-71981?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-71981, 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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