CVE-2026-33939

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-03-27. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-16858 (ENISA EUVD) · GHSA-9cx6-37pm-9jff (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g. {{*n}}), the compiled template calls lookupProperty(decorators, "n"), which returns undefined. The runtime then immediately invokes the result as a function, causing an unhandled TypeError: ... is not a function that crashes the Node.js process. Any application that compiles user-supplied templates without wrapping the call in a try/catch is vulnerable to a single-request Denial of Service. Version 4.7.9 fixes the issue. Some workarounds are available. Wrap compilation and rendering in try/catch. Validate template input before passing it to compile(); reject templates containing decorator syntax ({{*...}}) if decorators are not used in your application. Use the pre-compilation workflow; compile templates at build time and serve only pre-compiled templates; do not call compile() at request time.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
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 public PoC (CISA Vulnrichment) · Automatable yes (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: 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
0.6%
EPSS %ILE
50th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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 public PoC (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

March 27, 2026

Last Modified

October 26, 2026

Advisory Details (8)

Auto-updated Jul 7, 2026
Patch available. Sources: github_release, github, redhat, github_commit.
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 10",

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33939.json
GitHub advisoryMentions a patch (unverified)

Denial of Service via Malformed Decorator Syntax in Template Compilation · Advisory · handlebars-lang/handlebars.js · GitHub

https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-9cx6-37pm-9jff
Red HatMentions a patch (unverified)

2452508 – (CVE-2026-33939) CVE-2026-33939 handlebars.js: Handlebars.js: Denial of Service via malformed decorator syntax in template compilation

https://bugzilla.redhat.com/show_bug.cgi?id=2452508
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-33939
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:34342
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:10175
GitHub release Patch Available

v4.7.9

Patch available: handlebars-lang/handlebars.js v4.7.9

https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9
GitHub commit Patch Available

commit 68d8df5a88e0 (handlebars-lang/handlebars.js)

Patch available: handlebars-lang/handlebars.js v4.7.9 (contains commit 68d8df5a88e0)

https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatcluster-observability-operator/troubleshooting-panel-console-plugin-pf6-rhel9:17828399962026-07-01redhat
redhatdevspaces/code-rhel9:17767441102026-04-23redhat
npmhandlebars @ 4.7.9 (fixes >= 4.0.0, <= 4.7.8)—ghsa

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

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
node-handlebars3:4.7.6+~4.1.0-2 ... 3:4.7.9-5 (8 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
node-handlebars3:4.7.7+~4.1.0-1 ... 3:4.7.9-6 (7 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
node-handlebars3:4.7.7+~4.1.0-1 ... 3:4.7.9-6 (7 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
node-handlebars3:4.7.7+~4.1.0-1
  • every version up to 3:4.7.9-1: fixed in 3:4.7.9-1
—
npm(1)
PackageVulnerable rangeFix by version rangeDependents
handlebars—
  • 4.0.0 up to 4.7.9: fixed in 4.7.9
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 45× 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 98 of 175 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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 77 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  2. 2026-11-01 07:53 UTCGHSA enrichmentGHSA-9cx6-37pm-9jff · GitHub severity HIGH · GitHub CVSS 7.5
  3. 2026-11-01 07:53 UTCEG score recompute
  4. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  5. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  6. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  7. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  8. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  9. 2026-10-26 22:26 UTCEG score recompute
  10. 2026-10-26 22:26 UTCVendor advisory
  11. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  12. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-10-25 14:34 UTCEG score recompute
  14. 2026-10-24 18:02 UTCEG score recompute
  15. 2026-10-24 18:02 UTCVendor advisory
  16. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  17. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  18. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  19. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  20. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  21. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  22. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  23. 2026-10-18 03:46 UTCEG score recompute
  24. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  25. 2026-10-17 15:41 UTCEG score recompute
Show 73 more
  1. 2026-10-17 15:41 UTCVendor advisory
  2. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  3. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  4. 2026-10-14 19:24 UTCOSV refresh
  5. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  6. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  7. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  8. 2026-10-12 16:13 UTCEG score recompute
  9. 2026-10-11 19:55 UTCEG score recompute
  10. 2026-10-11 17:08 UTCEG score recompute
  11. 2026-10-11 14:35 UTCEG score recompute
  12. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  13. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  14. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  15. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  16. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  17. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  18. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  20. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  21. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  22. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  23. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  24. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  25. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  26. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  27. 2026-09-23 19:04 UTCOSV refresh
  28. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  29. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  30. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  31. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  32. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  33. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  34. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  35. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  36. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  37. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  38. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  39. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  40. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  41. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  42. 2026-09-04 13:30 UTCEG score recompute
  43. 2026-09-04 13:30 UTCVendor advisory
  44. 2026-09-04 12:23 UTCEG score recompute
  45. 2026-09-04 12:23 UTCVendor advisory
  46. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  47. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  48. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  49. 2026-09-01 13:51 UTCEG score recompute
  50. 2026-09-01 13:51 UTCVendor advisory
  51. 2026-09-01 12:24 UTCEG score recompute
  52. 2026-09-01 12:24 UTCVendor advisory
  53. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  54. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  55. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  56. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  57. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  58. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  59. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  60. 2026-08-24 14:17 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  61. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  62. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  63. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  64. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  65. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  66. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  67. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  68. 2026-08-16 09:56 UTCEG score recompute
  69. 2026-08-16 09:56 UTCVendor advisory
  70. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  71. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  72. 2026-08-14 19:25 UTCVendor advisory
  73. 2026-08-14 06:15 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-33939?
CVE-2026-33939 is a high-severity vulnerability; its CVE record was published on March 27, 2026. Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g. {{n}}), the compiled template calls lookupProperty(decorators, "n"), which returns…
When was the CVE record for CVE-2026-33939 published?
The CVE record for CVE-2026-33939 was published on March 27, 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 October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-33939 actively exploited?
CVE-2026-33939 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (50th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33939?
CVE-2026-33939 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-33939?
A fix for CVE-2026-33939 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-33939 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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