CVE-2026-0256

MEDIUMNVD 4.84.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 4.8 from GitHub Security Advisory published 2026-05-13. NVD baseline CVSS 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
4.8EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 4.8Exploit: None knownExposed services: Not assessed

PAN-OS 12.1 12.1.5 through 12.1.6 Upgrade to 12.1.7 or later (from the CVE record's solution, Palo Alto Networks, Inc.) — apply it.

A stored cross-site scripting (XSS) vulnerability in Palo Alto Networks PAN-OS® software enables a malicious authenticated administrator to store a JavaScript payload using the web interface.

This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series).

Cloud NGFW and Prisma® Access are not impacted by this vulnerability.

CVSS v3
4.8
EG Score
4.8MEDIUMmedium confidence
EG Risk
22
EG Risk 22/100

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 (value × EchelonGraph’s weight)
Severity48% × 45%
The EG Score, 4.8 of 10.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: PAN-OS 12.1 12.1.5 through 12.1.6 Upgrade to 12.1.7 or later (from the CVE record's solution, Palo Alto Networks, Inc.). Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
5th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

PAN-OS 12.1 12.1.5 through 12.1.6 Upgrade to 12.1.7 or later (from the CVE record's solution, Palo Alto Networks, Inc.). Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 13, 2026

Last Modified

July 14, 2026

Advisory Details (2)

Auto-updated Jun 17, 2026
Fix named in the CVE record's solution (Palo Alto Networks, Inc.).
Web page

CVE-2026-0256 PAN-OS: Stored Cross-Site Scripting (XSS) Vulnerability in the Web Interface

https://security.paloaltonetworks.com/CVE-2026-0256

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 24× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 228 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 128 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  2. 2026-10-12 16:42 UTCEG score recompute
  3. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  4. 2026-10-11 20:17 UTCEG score recompute
  5. 2026-10-11 18:29 UTCEG score recompute
  6. 2026-10-11 15:03 UTCEG score recompute
  7. 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  13. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  14. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  15. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  16. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  19. 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  20. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  21. 2026-09-23 13:47 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  22. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  23. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  24. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  25. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.2% · 7th percentile
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  1. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  2. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  3. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  4. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  5. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  6. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  7. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  8. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  9. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  10. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  11. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  12. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  13. 2026-08-30 01:21 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  14. 2026-08-28 21:40 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  15. 2026-08-27 14:24 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  16. 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  17. 2026-08-23 17:51 UTCEG score recompute
  18. 2026-08-23 17:51 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  19. 2026-08-21 23:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  20. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  21. 2026-08-20 19:48 UTCEG score recompute
  22. 2026-08-20 19:48 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  23. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  24. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  25. 2026-08-17 10:39 UTCEG score recompute
  26. 2026-08-17 10:39 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  27. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  28. 2026-08-16 04:03 UTCEG score recompute
  29. 2026-08-16 04:03 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  30. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  31. 2026-08-15 01:46 UTCEG score recompute
  32. 2026-08-15 01:46 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  33. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  34. 2026-08-14 02:31 UTCEG score recompute
  35. 2026-08-14 02:31 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  36. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  37. 2026-08-12 23:26 UTCEG score recompute
  38. 2026-08-12 23:26 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  39. 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  40. 2026-08-12 00:11 UTCEG score recompute
  41. 2026-08-12 00:11 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  42. 2026-08-11 13:42 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  43. 2026-08-11 00:56 UTCEG score recompute
  44. 2026-08-11 00:56 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  45. 2026-08-10 23:59 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  46. 2026-08-10 01:10 UTCEG score recompute
  47. 2026-08-10 01:10 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  48. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  49. 2026-08-09 01:54 UTCEG score recompute
  50. 2026-08-09 01:54 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  51. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  52. 2026-08-07 20:11 UTCEG score recompute
  53. 2026-08-07 20:11 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  54. 2026-08-06 20:56 UTCEG score recompute
  55. 2026-08-06 20:56 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  56. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  57. 2026-08-05 21:40 UTCEG score recompute
  58. 2026-08-05 21:40 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  59. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  60. 2026-08-04 15:09 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  61. 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  62. 2026-08-03 19:08 UTCEG score recompute
  63. 2026-08-03 19:08 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  64. 2026-08-03 10:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  65. 2026-08-02 19:03 UTCEG score recompute
  66. 2026-08-02 19:03 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  67. 2026-08-02 02:26 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  68. 2026-08-01 19:48 UTCEG score recompute
  69. 2026-08-01 19:48 UTCGHSA enrichmentGHSA-q845-rv2h-x553 · GitHub CVSS 4.8
  70. 2026-08-01 04:15 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  71. 2026-07-30 16:27 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  72. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  73. 2026-07-28 15:36 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  74. 2026-07-27 14:13 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  75. 2026-07-26 14:54 UTCEPSS rescoreEPSS 0.2% · 7th percentile

Frequently asked(5)

What is CVE-2026-0256?
CVE-2026-0256 is a medium-severity vulnerability; its CVE record was published on May 13, 2026. A stored cross-site scripting (XSS) vulnerability in Palo Alto Networks PAN-OS® software enables a malicious authenticated administrator to store a JavaScript payload using the web interface. This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual…
When was CVE-2026-0256 made public?
CVE-2026-0256 was made public on May 13, 2026: that is the date its CVE record's CNA, Palo Alto Networks, Inc., gives for when the vulnerability was made public. The CVE record itself was published on May 13, 2026. EchelonGraph's copy of the record carries a last-modified date of July 14, 2026; the record at its source may have been updated since.
Is CVE-2026-0256 actively exploited?
CVE-2026-0256 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (5th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-0256?
CVE-2026-0256 has a CVSS v3 base score of 4.8 (NVD).
How do I remediate CVE-2026-0256?
The CVE record's solution for CVE-2026-0256, written by its CNA Palo Alto Networks, Inc., names the fix: "PAN-OS 12.1 12.1.5 through 12.1.6 Upgrade to 12.1.7 or later." The vendor advisories EchelonGraph has for CVE-2026-0256 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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