CVE-2026-65053

MEDIUMPre-NVD 6.16.1
EchelonGraph scoreMEDIUM confidence

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

Score 6.1 from GitHub Security Advisory published 2026-08-24. A secondary CVSS source baseline 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this weekElevated
6.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (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: 0.4%CVSS: 6.1Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Horde IMP's AppleDouble MIME viewer writes an attacker-controlled attachment name into an HTML status block without escaping it. In lib/Mime/Viewer/Appledouble.php, _IMPrender() obtains the name of the data part with IMP_Contents::getPartName(), which returns the MIME part's own name parameter as supplied by the message, and passes it through sprintf into the text of an IMP_Mime_Status object. IMP_Mime_Status::__toString() concatenates each text entry directly into the surrounding table markup, so the value reaches the rendered page verbatim. A message crafted as multipart/appledouble whose data part carries markup in its name parameter therefore executes script in the context of any user who views it, and the payload persists in the mailbox. Exploitation requires no account on the target system, only the ability to send mail to a user. Version 7.2.0 escapes the value with htmlspecialchars(). The researcher additionally chains this flaw with the arbitrary file read of CVE-2026-58451, and reports that script running in an administrator's session can reach an application code-execution path.

CVSS v3
6.1
EG Score
6.1MEDIUMmedium confidence
EG Risk
43
EG Risk 43/100

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)
Severity61% × 45%
The EG Score, 6.1 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
33rd
KEV
Not listed

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

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (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

August 24, 2026

Last Modified

October 12, 2026

Advisory Details (5)

Auto-updated Aug 24, 2026
Patch available. Sources: github_commit, github_pr, github_release.
Web page

Horde IMP before 7.2.0 Stored Cross-Site Scripting via AppleDouble Viewer Part Name | Advisories | VulnCheck

https://www.vulncheck.com/advisories/horde-imp-before-stored-cross-site-scripting-via-appledouble-viewer-part-name
Web page

pre-auth RCE in horde groupware (CVE-2026-65053, CVE-2026-58451)

https://blog.evan.lat/posts/CVE-2026-65053/
GitHub release Patch Available

7.2.0

Patch available: horde/imp v7.2.0

https://github.com/horde/imp/releases/tag/v7.2.0
GitHub pull request Patch Available

fix: CVE-2026-65053 Stored Cross-Site Scripting (XSS) in Horde IMP AppleDouble MIME Viewer

Patch available: horde/imp v7.2.0 (PR #107 merged 2026-08-21)

https://github.com/horde/imp/pull/107
GitHub commit

commit f31449a12e3f (horde/imp)

Fix landed in horde/imp commit f31449a12e3f — awaiting tagged release

https://github.com/horde/imp/commit/f31449a12e3f945c90015d29524925c4c43f6324

Vendor Advisories for CVE-2026-65053(1)

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

Affected Packages

(1 across 1 ecosystem)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
php-horde-imp6.2.27-3, 6.2.27-3.1
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 77× 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 142 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 42 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  2. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  4. 2026-10-12 15:29 UTCEG score recompute
  5. 2026-10-12 15:29 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  6. 2026-10-11 19:32 UTCEG score recompute
  7. 2026-10-11 16:47 UTCEG score recompute
  8. 2026-10-11 14:08 UTCEG score recompute
  9. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  11. 2026-10-10 12:40 UTCEG score recompute
  12. 2026-10-10 12:40 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  13. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  14. 2026-10-09 05:50 UTCEG score recompute
  15. 2026-10-09 05:50 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  16. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  17. 2026-10-08 06:34 UTCEG score recompute
  18. 2026-10-08 06:34 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  19. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  20. 2026-10-07 07:16 UTCEG score recompute
  21. 2026-10-07 07:16 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  23. 2026-10-06 07:45 UTCEG score recompute
  24. 2026-10-06 07:45 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  25. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
Show 75 more
  1. 2026-10-05 04:46 UTCEG score recompute
  2. 2026-10-05 04:46 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  3. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  4. 2026-10-04 05:27 UTCEG score recompute
  5. 2026-10-04 05:27 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  6. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  7. 2026-10-03 06:14 UTCEG score recompute
  8. 2026-10-03 06:13 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  9. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  10. 2026-10-02 06:43 UTCEG score recompute
  11. 2026-10-02 06:43 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  12. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  13. 2026-10-01 06:27 UTCEG score recompute
  14. 2026-10-01 06:27 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  15. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  16. 2026-09-30 07:13 UTCEG score recompute
  17. 2026-09-30 07:13 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  18. 2026-09-28 23:22 UTCEG score recompute
  19. 2026-09-28 23:22 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  20. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  21. 2026-09-27 23:53 UTCEG score recompute
  22. 2026-09-27 23:53 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  23. 2026-09-27 00:38 UTCEG score recompute
  24. 2026-09-27 00:38 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  25. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  26. 2026-09-24 21:20 UTCEG score recompute
  27. 2026-09-24 21:20 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  28. 2026-09-24 19:13 UTCEG score recompute
  29. 2026-09-24 19:13 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  30. 2026-09-23 19:59 UTCEG score recompute
  31. 2026-09-23 19:59 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  32. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  33. 2026-09-22 19:30 UTCEG score recompute
  34. 2026-09-22 19:30 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  35. 2026-09-21 19:18 UTCEG score recompute
  36. 2026-09-21 19:18 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  37. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  38. 2026-09-20 20:03 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  39. 2026-09-19 20:49 UTCEG score recompute
  40. 2026-09-19 20:49 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  41. 2026-09-18 21:35 UTCEG score recompute
  42. 2026-09-18 21:35 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  43. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  44. 2026-09-17 22:08 UTCEG score recompute
  45. 2026-09-17 22:08 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  46. 2026-09-16 22:53 UTCEG score recompute
  47. 2026-09-16 22:53 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  48. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  49. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  50. 2026-09-15 23:36 UTCEG score recompute
  51. 2026-09-15 23:36 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  52. 2026-09-14 23:44 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  53. 2026-09-14 00:10 UTCEG score recompute
  54. 2026-09-14 00:10 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  55. 2026-09-13 00:55 UTCEG score recompute
  56. 2026-09-13 00:55 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  57. 2026-09-12 01:41 UTCEG score recompute
  58. 2026-09-12 01:41 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  59. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  60. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  61. 2026-09-11 02:27 UTCEG score recompute
  62. 2026-09-11 02:27 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  63. 2026-09-10 03:13 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  64. 2026-09-09 03:58 UTCEG score recompute
  65. 2026-09-09 03:58 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  66. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  67. 2026-09-08 04:44 UTCEG score recompute
  68. 2026-09-08 04:44 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  69. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  70. 2026-09-07 05:30 UTCEG score recompute
  71. 2026-09-07 05:30 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  72. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  73. 2026-09-06 06:15 UTCEG score recompute
  74. 2026-09-06 06:15 UTCGHSA enrichmentGHSA-8wpm-p8h2-x7wh · GitHub CVSS 6.1
  75. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-65053?
CVE-2026-65053 is a medium-severity vulnerability; its CVE record was published on August 24, 2026. Horde IMP's AppleDouble MIME viewer writes an attacker-controlled attachment name into an HTML status block without escaping it. In lib/Mime/Viewer/Appledouble.php, IMPrender() obtains the name of the data part with IMPContents::getPartName(), which returns the MIME part's own name parameter as…
When was CVE-2026-65053 made public?
CVE-2026-65053 was made public on August 5, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on August 24, 2026. EchelonGraph's copy of the record carries a last-modified date of October 12, 2026; the record at its source may have been updated since.
Is CVE-2026-65053 actively exploited?
CVE-2026-65053 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (33rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-65053?
CVE-2026-65053 has a CVSS base score of 6.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-65053?
A fix for CVE-2026-65053 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-65053 are linked in the Vendor Advisories panel on this page.

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