CVE-2026-81835

MEDIUMPre-NVD 5.55.5
EchelonGraph scoreMEDIUM confidence

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

Score 5.5 from GitHub Security Advisory (severity: LOW) published 2026-08-28. A secondary CVSS source baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated

Also known asEUVD-2026-67313 (ENISA EUVD) · GHSA-q2jq-8pm2-fj8h (GitHub Security Advisories)Source: ENISA EUVD

5.5EG
EchelonGraph verdictPlan mitigationNo fix is confirmed yet: check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule (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: 0.3%CVSS: 5.5Exploit: No code on recordExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

The CVE record's description, written by its CNA (VulDB), states the affected versions: "A security vulnerability has been detected in RooCodeInc Roo-Code up to 3.51.1." No release containing a fix is confirmed on record.

A security vulnerability has been detected in RooCodeInc Roo-Code up to 3.51.1. This affects the function fetch_instructions of the file malicious_mcp_server.py of the component MCP Integration Trust Model. The manipulation leads to code injection. The attack is possible to be carried out remotely. The exploit has been disclosed publicly and may be used. Multiple isses were reported to the vendor beforehand. They explain, that "they all apply to Roo Code, a project we no longer support - the repository was archived a while ago, and we don't encourage anyone to use it." This vulnerability only affects products that are no longer supported by the maintainer.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
41
EG Risk 41/100

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)
Severity55% × 45%
Impact severity (EG Severity): CVSS 5.5 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.
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: No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.
EPSS PROB
0.3%
EPSS %ILE
22nd
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 (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.

EG Severity
5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.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; Track* at high (mission-essential systems).

No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.

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.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.

The score's inputs: 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 27, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 27, 2026
No fix on record yet.
Web page

Security Advisory: Roo-Code Untrusted MCP Server Can Inject Arbitrary System Instructions · GitHub

https://gist.github.com/tchen200311/05b5960272c290b7843d6bbdbfe9f7c1

Vendor Advisories for CVE-2026-81835(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 31× 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 173 rows 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 73 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-11-08 16:41 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-11-07 16:40 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  7. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  8. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  9. 2026-11-04 16:37 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  11. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  12. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  13. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  14. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  15. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  16. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  17. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  18. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  19. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  20. 2026-10-25 13:58 UTCEchelonGraph re-scored
  21. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  22. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  23. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  24. 2026-10-22 13:47 UTCEchelonGraph re-scored
  25. 2026-10-22 13:47 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
Show 75 more
  1. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  2. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  3. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  4. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  5. 2026-10-18 03:09 UTCEchelonGraph re-scored
  6. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  7. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  8. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  9. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  10. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  11. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  12. 2026-10-12 14:56 UTCEchelonGraph re-scored
  13. 2026-10-11 19:20 UTCEchelonGraph re-scored
  14. 2026-10-11 16:36 UTCEchelonGraph re-scored
  15. 2026-10-11 13:54 UTCEchelonGraph re-scored
  16. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  17. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  18. 2026-10-10 01:45 UTCEchelonGraph re-scored
  19. 2026-10-10 01:45 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  20. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  21. 2026-10-09 02:55 UTCEchelonGraph re-scored
  22. 2026-10-09 02:55 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  23. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  24. 2026-10-08 01:13 UTCEchelonGraph re-scored
  25. 2026-10-08 01:13 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  26. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  27. 2026-10-06 22:42 UTCEchelonGraph re-scored
  28. 2026-10-06 22:42 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  29. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  30. 2026-10-06 00:51 UTCEchelonGraph re-scored
  31. 2026-10-06 00:51 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  32. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  33. 2026-10-04 23:52 UTCEchelonGraph re-scored
  34. 2026-10-04 23:52 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  35. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  36. 2026-10-04 02:00 UTCEchelonGraph re-scored
  37. 2026-10-04 02:00 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  38. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  39. 2026-10-03 04:09 UTCEchelonGraph re-scored
  40. 2026-10-03 04:09 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  41. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  42. 2026-10-02 06:18 UTCEchelonGraph re-scored
  43. 2026-10-02 06:18 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  44. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  45. 2026-10-01 07:54 UTCEchelonGraph re-scored
  46. 2026-10-01 07:54 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  47. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  48. 2026-09-30 10:03 UTCEchelonGraph re-scored
  49. 2026-09-30 10:03 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  50. 2026-09-29 12:12 UTCEchelonGraph re-scored
  51. 2026-09-29 12:12 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  52. 2026-09-28 14:06 UTCEchelonGraph re-scored
  53. 2026-09-28 14:06 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  54. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  55. 2026-09-27 16:15 UTCEchelonGraph re-scored
  56. 2026-09-27 16:14 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  57. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  58. 2026-09-26 18:23 UTCEchelonGraph re-scored
  59. 2026-09-26 18:23 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  60. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  61. 2026-09-25 12:22 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  62. 2026-09-24 14:31 UTCEchelonGraph re-scored
  63. 2026-09-24 14:31 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  64. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  65. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  66. 2026-09-23 16:12 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  67. 2026-09-22 18:22 UTCEchelonGraph re-scored
  68. 2026-09-22 18:21 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  69. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  70. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  71. 2026-09-21 20:27 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  72. 2026-09-20 22:31 UTCEchelonGraph re-scored
  73. 2026-09-20 22:30 UTCGHSA enrichmentGHSA-q2jq-8pm2-fj8h · GitHub severity LOW · GitHub CVSS 5.5
  74. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  75. 2026-09-20 00:39 UTCEchelonGraph re-scored

Frequently asked(5)

What is CVE-2026-81835?
CVE-2026-81835 is a medium-severity vulnerability; its CVE record was published on August 27, 2026. A security vulnerability has been detected in RooCodeInc Roo-Code up to 3.51.1. This affects the function fetch_instructions of the file malicious_mcp_server.py of the component MCP Integration Trust Model. The manipulation leads to code injection. The attack is possible to be carried out remotely.…
When was the CVE record for CVE-2026-81835 published?
The CVE record for CVE-2026-81835 was published on August 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 August 28, 2026; the record at its source may have been updated since.
Is CVE-2026-81835 actively exploited?
CVE-2026-81835 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81835?
CVE-2026-81835 has a CVSS base score of 5.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-81835?
No fix for CVE-2026-81835 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The CVE record's description, written by its CNA (VulDB), states the affected versions: "A security vulnerability has been detected in RooCodeInc Roo-Code up to 3.51.1." No release containing a fix is confirmed on record. The vendor advisories EchelonGraph has for CVE-2026-81835 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-81835

Explore →

Is Your Infrastructure Affected by CVE-2026-81835?

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