CVE-2026-54742

MEDIUMPre-NVD 5.15.1
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 5.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (44th 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
5.1EG
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: 0.5%CVSS: 5.1Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Lemmy is a link aggregator and forum for the fediverse. From 0.19.18 until 0.19.19 and 1.0.0-alpha.20, a community moderator can feature or unfeature posts in other communities through federated CollectionAdd and CollectionRemove activities using CollectionType::Featured. After verify_mod_action authorizes the actor against self.community(), the receive handlers in crates/apub/activities/src/community/collection_add.rs and crates/apub/activities/src/community/collection_remove.rs dereference self.object as an ApubPost and update featured_community without verifying that post.community_id equals community.id. A moderator can therefore target an unrelated post owned by another community, push it into featured feeds and listings, or undo another community's legitimate curation decision. This issue is fixed in versions 0.19.19 and 1.0.0-alpha.20.

CVSS v3
5.1
EG Score
5.1MEDIUMmedium confidence
EG Risk
39
EG Risk 39/100

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)
Severity51% × 45%
The EG Score, 5.1 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
0.5%
EPSS %ILE
44th
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 19, 2026

Last Modified

September 9, 2026

Advisory Details (8)

Auto-updated Aug 19, 2026
Patch available. Sources: github_pr, github_commit, github_release, github.
Web page

2026-06-09 - Lemmy Release v0.19.19

https://join-lemmy.org/news/2026-06-09_-_Lemmy_Release_v0.19.19
GitHub release Patch Available

1.0.0-alpha.20

Patch available: LemmyNet/lemmy 1.0.0-alpha.20 (pre-release)

https://github.com/LemmyNet/lemmy/releases/tag/1.0.0-alpha.20
GitHub release Patch Available

0.19.19

Patch available: LemmyNet/lemmy 0.19.19

https://github.com/LemmyNet/lemmy/releases/tag/0.19.19
GitHub commit Patch Available

commit abe256243822 (LemmyNet/lemmy)

Patch available: LemmyNet/lemmy 0.19.19 (contains commit abe256243822)

https://github.com/LemmyNet/lemmy/commit/abe256243822526dcd4bca857f7c0adeb49944f5
GitHub commit Patch Available

commit 108d78c592cc (LemmyNet/lemmy)

Patch available: LemmyNet/lemmy 1.0.0-beta.0 (contains commit 108d78c592cc)

https://github.com/LemmyNet/lemmy/commit/108d78c592cc88bac2b0bf52ca6631be54f6fb23
GitHub pull request Patch Available

For federated post feature, write modlog and validate community

Patch available: LemmyNet/lemmy 1.0.0-beta.0 (PR #6501 merged 2026-05-18)

https://github.com/LemmyNet/lemmy/pull/6501
GitHub pull request Patch Available

[0.19] For federated post feature, write modlog and validate community

Patch available: LemmyNet/lemmy 0.19.19 (PR #6500 merged 2026-05-18)

https://github.com/LemmyNet/lemmy/pull/6500
GitHub advisoryMentions a patch (unverified)

`CollectionAdd::Featured` does not check the post is in the community · Advisory · LemmyNet/lemmy · GitHub

https://github.com/LemmyNet/lemmy/security/advisories/GHSA-gwfj-h8r7-792v

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 51× 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.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  3. 2026-10-12 15:56 UTCEG score recompute
  4. 2026-10-11 19:39 UTCEG score recompute
  5. 2026-10-11 16:54 UTCEG score recompute
  6. 2026-10-11 14:17 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  10. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  11. 2026-10-08 07:24 UTCEG score recompute
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  13. 2026-10-07 07:23 UTCEG score recompute
  14. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  15. 2026-10-06 07:54 UTCEG score recompute
  16. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-10-05 05:22 UTCEG score recompute
  18. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  19. 2026-10-04 06:07 UTCEG score recompute
  20. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  21. 2026-10-03 06:52 UTCEG score recompute
  22. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  23. 2026-10-02 07:09 UTCEG score recompute
  24. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  25. 2026-10-01 07:52 UTCEG score recompute
Show 72 more
  1. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-09-30 08:37 UTCEG score recompute
  3. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  4. 2026-09-29 04:27 UTCEG score recompute
  5. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  6. 2026-09-28 05:11 UTCEG score recompute
  7. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-09-27 05:57 UTCEG score recompute
  9. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-09-24 19:34 UTCEG score recompute
  11. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-09-23 20:08 UTCEG score recompute
  13. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-09-22 19:48 UTCEG score recompute
  15. 2026-09-20 20:22 UTCEG score recompute
  16. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-09-19 21:07 UTCEG score recompute
  18. 2026-09-18 21:41 UTCEG score recompute
  19. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  20. 2026-09-17 21:28 UTCEG score recompute
  21. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  22. 2026-09-16 20:05 UTCEG score recompute
  23. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  24. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-09-15 18:50 UTCEG score recompute
  26. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  27. 2026-09-13 19:38 UTCEG score recompute
  28. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  29. 2026-09-12 20:23 UTCEG score recompute
  30. 2026-09-11 21:08 UTCEG score recompute
  31. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  32. 2026-09-10 21:52 UTCEG score recompute
  33. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  34. 2026-09-09 02:29 UTCEG score recompute
  35. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  36. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  37. 2026-09-07 09:33 UTCEG score recompute
  38. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  39. 2026-09-06 09:55 UTCEG score recompute
  40. 2026-09-05 10:40 UTCEG score recompute
  41. 2026-09-04 11:24 UTCEG score recompute
  42. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  43. 2026-09-03 12:09 UTCEG score recompute
  44. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  45. 2026-09-02 12:45 UTCEG score recompute
  46. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  47. 2026-09-01 13:25 UTCEG score recompute
  48. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  49. 2026-08-31 14:10 UTCEG score recompute
  50. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  51. 2026-08-30 13:35 UTCEG score recompute
  52. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  53. 2026-08-29 14:18 UTCEG score recompute
  54. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  55. 2026-08-27 15:37 UTCEG score recompute
  56. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  57. 2026-08-26 16:14 UTCEG score recompute
  58. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  59. 2026-08-25 16:37 UTCEG score recompute
  60. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  61. 2026-08-24 17:23 UTCEG score recompute
  62. 2026-08-23 18:05 UTCEG score recompute
  63. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  64. 2026-08-22 18:50 UTCEG score recompute
  65. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  66. 2026-08-21 19:35 UTCEG score recompute
  67. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  68. 2026-08-20 20:20 UTCEG score recompute
  69. 2026-08-20 20:17 UTCEG score recompute
  70. 2026-08-19 20:19 UTCEG score recompute
  71. 2026-08-19 20:13 UTCEG score recomputeFirst assessed: 5.1 MEDIUM
  72. 2026-08-19 20:12 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-54742?
CVE-2026-54742 is a medium-severity vulnerability; its CVE record was published on August 19, 2026. Lemmy is a link aggregator and forum for the fediverse. From 0.19.18 until 0.19.19 and 1.0.0-alpha.20, a community moderator can feature or unfeature posts in other communities through federated CollectionAdd and CollectionRemove activities using CollectionType::Featured. After verifymodaction…
When was the CVE record for CVE-2026-54742 published?
The CVE record for CVE-2026-54742 was published on August 19, 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 September 9, 2026; the record at its source may have been updated since.
Is CVE-2026-54742 actively exploited?
CVE-2026-54742 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (44th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-54742?
CVE-2026-54742 has a CVSS base score of 5.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-54742?
A fix for CVE-2026-54742 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-54742

Explore →

Is Your Infrastructure Affected by CVE-2026-54742?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs