CVE-2026-53511

HIGHPre-NVD 8.58.5
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (9th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated
8.5EG
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: 0.2%CVSS: 8.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

calibre is an e-book manager. Prior to 9.10.0, a malicious EPUB, OPF, or PDF file can execute arbitrary Python code when its metadata is read by calibre, including through Add books or Edit books, by embedding a custom column definition with a python: template in calibre:user_metadata that is passed unsanitized to exec() in the template formatter. This issue is fixed in version 9.10.0.

CVSS v3
8.5
EG Score
8.5HIGHmedium confidence
EG Risk
54
EG Risk 54/100

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)
Severity85% × 45%
The EG Score, 8.5 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, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (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
9th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

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 no (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)14 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 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 7, 2026

Last Modified

August 18, 2026

Advisory Details (3)

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

Arbitrary Code Execution in Template Formatter via Book Metadata · Advisory · kovidgoyal/calibre · GitHub

https://github.com/kovidgoyal/calibre/security/advisories/GHSA-2j4m-2q7x-2c47
GitHub release Patch Available

version 9.10.0

Patch available: kovidgoyal/calibre v9.10.0

https://github.com/kovidgoyal/calibre/releases/tag/v9.10.0
GitHub commit Patch Available

commit 712f4e1ff5c1 (kovidgoyal/calibre)

Patch available: kovidgoyal/calibre v9.10.0 (contains commit 712f4e1ff5c1)

https://github.com/kovidgoyal/calibre/commit/712f4e1ff5c1e798c335bef3bacc4efdee052e9c

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
calibre6.13.0+repack-2 ... 6.13.0+repack-2+deb12u9 (10 versions)
  • every version up to 6.13.0+repack-2+deb12u10: fixed in 6.13.0+repack-2+deb12u10
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
calibre8.10.0+ds-1 ... 9.9.0+ds+~0.10.6-1 (73 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
calibre8.10.0+ds-1 ... 9.9.0+ds+~0.10.6-1 (59 versions)
  • every version up to 9.10.0+ds+~0.10.6-1: fixed in 9.10.0+ds+~0.10.6-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 32× 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 138 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 38 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-17 09:19 UTCEG score recompute
  2. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  3. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  4. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  5. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  6. 2026-10-12 15:57 UTCEG score recompute
  7. 2026-10-11 19:40 UTCEG score recompute
  8. 2026-10-11 16:55 UTCEG score recompute
  9. 2026-10-11 14:19 UTCEG score recompute
  10. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  11. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  13. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  15. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  16. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  17. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  18. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  19. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  21. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  22. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  23. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  24. 2026-09-28 13:35 UTCEG score recompute
  25. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 8th percentile
Show 75 more
  1. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  2. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  3. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  4. 2026-09-23 06:16 UTCEG score recompute
  5. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  6. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  7. 2026-09-18 05:49 UTCEG score recompute
  8. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  9. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-09-13 23:53 UTCEG score recompute
  11. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  12. 2026-09-12 03:42 UTCEG score recompute
  13. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  14. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  15. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  16. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  17. 2026-09-06 14:07 UTCEG score recompute
  18. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  19. 2026-09-05 22:53 UTCEG score recompute
  20. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  21. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  22. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  23. 2026-08-30 19:17 UTCEG score recompute
  24. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  25. 2026-08-30 07:42 UTCEG score recompute
  26. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  27. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  28. 2026-08-27 21:55 UTCEG score recompute
  29. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  30. 2026-08-27 01:55 UTCEG score recompute
  31. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  32. 2026-08-26 12:58 UTCEG score recompute
  33. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  34. 2026-08-24 20:38 UTCEG score recompute
  35. 2026-08-23 03:16 UTCEG score recompute
  36. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  37. 2026-08-22 03:57 UTCEG score recompute
  38. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  39. 2026-08-21 04:11 UTCEG score recompute
  40. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  41. 2026-08-20 02:11 UTCEG score recompute
  42. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  43. 2026-08-18 20:47 UTCEG score recompute
  44. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  45. 2026-08-18 08:30 UTCEG score recompute
  46. 2026-08-18 07:37 UTCEG score recompute
  47. 2026-08-17 22:33 UTCEG score recompute
  48. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  49. 2026-08-16 21:47 UTCEG score recompute
  50. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  51. 2026-08-16 10:11 UTCEG score recompute
  52. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  53. 2026-08-15 11:02 UTCEG score recompute
  54. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  55. 2026-08-14 00:17 UTCEG score recompute
  56. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  57. 2026-08-13 01:06 UTCEG score recompute
  58. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  59. 2026-08-11 14:21 UTCEG score recompute
  60. 2026-08-11 02:46 UTCEG score recompute
  61. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  62. 2026-08-09 16:01 UTCEG score recompute
  63. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  64. 2026-08-07 17:41 UTCEG score recompute
  65. 2026-08-06 18:30 UTCEG score recompute
  66. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  67. 2026-08-05 19:20 UTCEG score recompute
  68. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  69. 2026-08-04 20:08 UTCEG score recompute
  70. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  71. 2026-08-04 10:39 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  72. 2026-08-03 19:25 UTCEG score recompute
  73. 2026-08-03 10:36 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  74. 2026-08-02 08:40 UTCEG score recompute
  75. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.1% · 4th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-53511?
CVE-2026-53511 is a high-severity vulnerability; its CVE record was published on July 7, 2026. calibre is an e-book manager. Prior to 9.10.0, a malicious EPUB, OPF, or PDF file can execute arbitrary Python code when its metadata is read by calibre, including through Add books or Edit books, by embedding a custom column definition with a python: template in calibre:user_metadata that is…
When was the CVE record for CVE-2026-53511 published?
The CVE record for CVE-2026-53511 was published on July 7, 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 August 18, 2026; the record at its source may have been updated since.
Is CVE-2026-53511 actively exploited?
CVE-2026-53511 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (9th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-53511?
CVE-2026-53511 has a CVSS base score of 8.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-53511?
A fix for CVE-2026-53511 is available: update to the fixed version the vendor names in its advisory.

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