CVE-2026-34745

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.6% (50th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Elevated

Also known asEUVD-2026-18507 (ENISA EUVD)Source: ENISA EUVD

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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.1Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Fireshare facilitates self-hosted media and link sharing. Prior to version 1.5.3, the fix for CVE-2026-33645 was applied to the authenticated /api/uploadChunked endpoint but was not applied to the unauthenticated /api/uploadChunked/public endpoint in the same file (app/server/fireshare/api.py). An unauthenticated attacker can exploit the checkSum parameter to write arbitrary files with attacker-controlled content to any writable path on the server filesystem. This issue has been patched in version 1.5.3.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
72
EG Risk 72/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). 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

April 2, 2026

Last Modified

July 24, 2026

Advisory Details (4)

Auto-updated Sep 16, 2026
Patch available. Sources: github_pr, github_release, github, github_commit.
GitHub advisoryMentions a patch (unverified)

Unauthenticated Path Traversal Arbitrary File Write in /api/uploadChunked/public · Advisory · ShaneIsrael/fireshare · GitHub

https://github.com/ShaneIsrael/fireshare/security/advisories/GHSA-fvvp-rj8g-c7gc
GitHub release Patch Available

v1.5.3

Patch available: ShaneIsrael/fireshare v1.5.3

https://github.com/ShaneIsrael/fireshare/releases/tag/v1.5.3
GitHub pull request Patch Available

fix path traversal vulnerability in public upload

Patch available: ShaneIsrael/fireshare v1.5.7 (PR #520 merged 2026-03-30)

https://github.com/ShaneIsrael/fireshare/pull/520
GitHub commit Patch Available

commit b76915607924 (ShaneIsrael/fireshare)

Patch available: ShaneIsrael/fireshare v1.5.7 (contains commit b76915607924)

https://github.com/ShaneIsrael/fireshare/commit/b76915607924756e6fa1a5f6c8823c38d611fb24

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 254 rows on record for this CVE, as 99 entries (1 repeat merged).

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. 1 repeat row among the latest 100 is merged into the row it repeats. The 154 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 17:02 UTCEchelonGraph re-scored
  2. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  3. 2026-11-11 18:39 UTCEchelonGraph re-scored
  4. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  5. 2026-11-10 20:17 UTCEchelonGraph re-scored
  6. 2026-11-10 16:43 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  7. 2026-11-09 21:56 UTCEchelonGraph re-scored
  8. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  9. 2026-11-08 23:35 UTCEchelonGraph re-scored
  10. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  11. 2026-11-08 01:13 UTCEchelonGraph re-scored
  12. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  13. 2026-11-07 02:48 UTCEchelonGraph re-scored
  14. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  15. 2026-11-06 06:55 UTCOSV refresh
  16. 2026-11-06 04:27 UTCEchelonGraph re-scored
  17. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  18. 2026-11-05 06:06 UTCEchelonGraph re-scored
  19. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  20. 2026-11-04 07:43 UTCEchelonGraph re-scored
  21. 2026-11-03 16:47 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  22. 2026-11-03 09:22 UTCEchelonGraph re-scored
  23. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  24. 2026-11-02 11:01 UTCEchelonGraph re-scored
  25. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.6% · 50th percentile
Show 74 more
  1. 2026-11-01 12:39 UTCEchelonGraph re-scored
  2. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  3. 2026-10-31 14:18 UTCEchelonGraph re-scored
  4. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  5. 2026-10-29 17:36 UTCEchelonGraph re-scored
  6. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  7. 2026-10-28 19:14 UTCEchelonGraph re-scored
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  9. 2026-10-27 20:50 UTCEchelonGraph re-scored
  10. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  11. 2026-10-26 22:25 UTCEchelonGraph re-scored
  12. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-10-25 21:10 UTCEchelonGraph re-scored
  14. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  15. 2026-10-25 14:33 UTCEchelonGraph re-scored
  16. 2026-10-24 22:49 UTCEchelonGraph re-scored
  17. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  18. 2026-10-24 00:28 UTCEchelonGraph re-scored
  19. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  20. 2026-10-23 01:57 UTCEchelonGraph re-scored
  21. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  22. 2026-10-22 03:35 UTCEchelonGraph re-scored
  23. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  24. 2026-10-21 05:14 UTCEchelonGraph re-scored
  25. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  26. 2026-10-20 06:53 UTCEchelonGraph re-scored
  27. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  28. 2026-10-19 08:29 UTCEchelonGraph re-scored
  29. 2026-10-18 03:45 UTCEchelonGraph re-scored
  30. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  31. 2026-10-17 11:40 UTCEchelonGraph re-scored
  32. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  33. 2026-10-16 13:16 UTCEchelonGraph re-scored
  34. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  35. 2026-10-15 14:52 UTCEchelonGraph re-scored
  36. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  37. 2026-10-14 09:20 UTCEchelonGraph re-scored
  38. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  39. 2026-10-13 06:42 UTCEchelonGraph re-scored
  40. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  41. 2026-10-12 16:12 UTCEchelonGraph re-scored
  42. 2026-10-11 19:54 UTCEchelonGraph re-scored
  43. 2026-10-11 17:07 UTCEchelonGraph re-scored
  44. 2026-10-11 14:34 UTCEchelonGraph re-scored
  45. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  46. 2026-10-11 02:31 UTCOSV refresh
  47. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  48. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  49. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  50. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  51. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  52. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  53. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  54. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  55. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  56. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  57. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  58. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  59. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  60. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  61. 2026-09-21 13:49 UTCOSV refresh
  62. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  63. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  64. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  65. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  66. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  67. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  68. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  69. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  70. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  71. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  72. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  73. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  74. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.6% · 47th percentile

Frequently asked(5)

What is CVE-2026-34745?
CVE-2026-34745 is a critical-severity vulnerability; its CVE record was published on April 2, 2026. Fireshare facilitates self-hosted media and link sharing. Prior to version 1.5.3, the fix for CVE-2026-33645 was applied to the authenticated /api/uploadChunked endpoint but was not applied to the unauthenticated /api/uploadChunked/public endpoint in the same file (app/server/fireshare/api.py). An…
When was the CVE record for CVE-2026-34745 published?
The CVE record for CVE-2026-34745 was published on April 2, 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 24, 2026; the record at its source may have been updated since.
Is CVE-2026-34745 actively exploited?
CVE-2026-34745 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-2026-34745?
CVE-2026-34745 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-34745?
A fix for CVE-2026-34745 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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