CVE-2026-15747

CRITICALPre-NVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-14. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 3 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Fixed versions, as the CVE record's CNA (CPAN Security Group) states them: "Upgrade to Mojolicious 9.48 or later."

Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle.

_csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden csrf_token input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle.

An attacker able to query it can recover the token and pass csrf_protect validation.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

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)
Severity91% × 45%
The EG Score, 9.1 of 10.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.2%
EPSS %ILE
15th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (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

July 14, 2026

Last Modified

July 15, 2026

Advisory Details (3)

Auto-updated Sep 16, 2026
Patch available.
Web page

oss-security - CVE-2026-15747: Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle

http://www.openwall.com/lists/oss-security/2026/07/14/16

Vendor Advisories for CVE-2026-15747(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 rangeFix by version rangeDependents
libmojolicious-perl8.71+dfsg-1 ... 9.48+dfsg-1 (29 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
libmojolicious-perl9.31+dfsg-1 ... 9.48+dfsg-1 (18 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
libmojolicious-perl9.39+dfsg-1 ... 9.48+dfsg-1 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
libmojolicious-perl9.39+dfsg-1 ... 9.47+dfsg-1 (7 versions)
  • every version up to 9.48+dfsg-1: fixed in 9.48+dfsg-1
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 43× 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 362 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 262 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 09:50 UTCEG score recompute
  2. 2026-10-14 09:50 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  4. 2026-10-13 07:44 UTCEG score recompute
  5. 2026-10-13 07:43 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  6. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  7. 2026-10-12 16:31 UTCEG score recompute
  8. 2026-10-12 09:38 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  9. 2026-10-11 20:09 UTCEG score recompute
  10. 2026-10-11 17:22 UTCEG score recompute
  11. 2026-10-11 14:55 UTCEG score recompute
  12. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  13. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  14. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  15. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  16. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  17. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  18. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  19. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  20. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  21. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  22. 2026-10-01 13:02 UTCEG score recompute
  23. 2026-10-01 13:02 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  24. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  25. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.2% · 14th percentile
Show 75 more
  1. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  2. 2026-09-28 13:17 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-09-28 09:11 UTCEG score recompute
  4. 2026-09-28 09:11 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  5. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  6. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-09-24 09:10 UTCEG score recompute
  8. 2026-09-24 09:10 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  9. 2026-09-23 11:42 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  10. 2026-09-23 07:39 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  11. 2026-09-23 03:43 UTCEG score recompute
  12. 2026-09-23 03:43 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  13. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  14. 2026-09-18 10:01 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  15. 2026-09-18 04:53 UTCEG score recompute
  16. 2026-09-18 04:53 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  17. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  18. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  19. 2026-09-14 11:06 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  20. 2026-09-14 07:11 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  21. 2026-09-14 03:16 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  22. 2026-09-13 23:21 UTCEG score recompute
  23. 2026-09-13 23:21 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  24. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  25. 2026-09-13 16:26 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  26. 2026-09-13 11:50 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  27. 2026-09-13 07:46 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  28. 2026-09-12 17:10 UTCEG score recompute
  29. 2026-09-12 17:10 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  30. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  31. 2026-09-12 13:15 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  32. 2026-09-12 07:27 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  33. 2026-09-12 01:27 UTCEG score recompute
  34. 2026-09-12 01:27 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  35. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  36. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  37. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  38. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  39. 2026-09-08 01:27 UTCEG score recompute
  40. 2026-09-08 01:27 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  41. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  42. 2026-09-06 17:49 UTCEG score recompute
  43. 2026-09-06 17:49 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  44. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  45. 2026-09-06 13:41 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  46. 2026-09-06 05:28 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  47. 2026-09-06 01:32 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  48. 2026-09-05 21:11 UTCEG score recompute
  49. 2026-09-05 21:11 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  50. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  51. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  52. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  53. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  54. 2026-08-31 05:00 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  55. 2026-08-31 00:46 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  56. 2026-08-30 20:51 UTCEG score recompute
  57. 2026-08-30 20:51 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  58. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  59. 2026-08-30 16:56 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  60. 2026-08-30 13:01 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  61. 2026-08-30 08:42 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  62. 2026-08-30 04:47 UTCEG score recompute
  63. 2026-08-30 04:47 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  64. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  65. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  66. 2026-08-28 01:57 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  67. 2026-08-27 21:31 UTCEG score recompute
  68. 2026-08-27 21:31 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  69. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  70. 2026-08-27 13:22 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  71. 2026-08-27 03:41 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  72. 2026-08-26 23:31 UTCEG score recompute
  73. 2026-08-26 23:31 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1
  74. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  75. 2026-08-26 12:13 UTCGHSA enrichmentGHSA-6cg9-7rr8-cvj2 · GitHub severity CRITICAL · GitHub CVSS 9.1

Frequently asked(5)

What is CVE-2026-15747?
CVE-2026-15747 is a critical-severity vulnerability; its CVE record was published on July 14, 2026. Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle. csrftoken generates and caches one token per session and returns the same value on every call, and csrffield places that value in a hidden csrf_token input.…
When was the CVE record for CVE-2026-15747 published?
The CVE record for CVE-2026-15747 was published on July 14, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 15, 2026; the record at its source may have been updated since.
Is CVE-2026-15747 actively exploited?
CVE-2026-15747 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (15th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-15747?
CVE-2026-15747 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-15747?
A fix for CVE-2026-15747 is available: update to the fixed version the vendor names in its advisory. Fixed versions, as the CVE record's CNA (CPAN Security Group) states them: "Upgrade to Mojolicious 9.48 or later." The vendor advisories EchelonGraph has for CVE-2026-15747 are linked in the Vendor Advisories panel on this page.

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