CVE-2026-77641

HIGHNVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.2 under NVD CVSS v3. EPSS exploit probability: 0.4% (26th percentile of EPSS-scored CVEs). GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.2Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

tor before 0.4.9.9 was prone to a NULL write after free when sending a CONFLUX_SWITCH cell fails. The return value of relay_send_command_from_edge() was ignored, so a send failure (which calls circuit_mark_for_close() and removes the leg via cfx_del_leg()) would go undetected, causing the caller to write to the now-freed current leg and resulting in a crash. This is TROVE-2026-017.

CVSS v3
8.2
EG Score
8.2HIGHmedium confidence
EG Risk
37
EG Risk 37/100CISA SSVC

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
Severity82% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
26th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 20, 2026

Last Modified

September 8, 2026

References (1)

Vendor Advisories for CVE-2026-77641(1)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
tor0.4.7.13-1 ... 0.4.9.9-1~bpo13+1 (46 versions)
  • every version up to 0.4.9.9-1: fixed in 0.4.9.9-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
tor0.4.8.16-1 ... 0.4.9.9-1~bpo13+1 (22 versions)
  • every version up to 0.4.9.11-0+deb13u1: fixed in 0.4.9.11-0+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
tor0.4.8.16-1 ... 0.4.9.9-1~bpo13+1 (19 versions)
  • every version up to 0.4.9.9-1: fixed in 0.4.9.9-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 24× in last 7d / 107× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 151 total refreshes for this CVE.

  1. 2026-10-05 04:57 UTCEG score recompute
  2. 2026-10-05 04:57 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 15:40 UTCGHSA enrichment
  5. 2026-10-04 04:12 UTCGHSA enrichment
  6. 2026-10-03 16:46 UTCEG score recompute
  7. 2026-10-03 16:46 UTCGHSA enrichment
  8. 2026-10-03 14:26 UTCEPSS rescore
  9. 2026-10-02 21:00 UTCEG score recompute
  10. 2026-10-02 21:00 UTCGHSA enrichment
  11. 2026-10-02 09:12 UTCGHSA enrichment
  12. 2026-10-01 21:28 UTCEG score recompute
  13. 2026-10-01 21:28 UTCGHSA enrichment
  14. 2026-10-01 19:50 UTCEPSS rescore
  15. 2026-10-01 07:59 UTCGHSA enrichment
  16. 2026-09-30 20:30 UTCEG score recompute
  17. 2026-09-30 20:30 UTCGHSA enrichment
  18. 2026-09-30 08:08 UTCEG score recompute
  19. 2026-09-30 08:08 UTCGHSA enrichment
  20. 2026-09-29 15:24 UTCEPSS rescore
  21. 2026-09-29 01:53 UTCEG score recompute
  22. 2026-09-29 01:53 UTCGHSA enrichment
  23. 2026-09-28 13:52 UTCEPSS rescore
  24. 2026-09-28 13:47 UTCGHSA enrichment
  25. 2026-09-28 02:19 UTCGHSA enrichment
Show 75 more
  1. 2026-09-27 14:52 UTCEG score recompute
  2. 2026-09-27 14:51 UTCGHSA enrichment
  3. 2026-09-27 13:48 UTCEPSS rescore
  4. 2026-09-27 02:54 UTCEG score recompute
  5. 2026-09-27 02:54 UTCGHSA enrichment
  6. 2026-09-26 15:59 UTCEPSS rescore
  7. 2026-09-26 00:28 UTCEPSS rescore
  8. 2026-09-25 06:32 UTCGHSA enrichment
  9. 2026-09-24 19:05 UTCEG score recompute
  10. 2026-09-24 19:05 UTCGHSA enrichment
  11. 2026-09-24 14:04 UTCEPSS rescore
  12. 2026-09-24 07:31 UTCGHSA enrichment
  13. 2026-09-23 20:03 UTCEG score recompute
  14. 2026-09-23 20:03 UTCGHSA enrichment
  15. 2026-09-23 17:54 UTCEPSS rescore
  16. 2026-09-23 07:12 UTCGHSA enrichment
  17. 2026-09-22 19:45 UTCEG score recompute
  18. 2026-09-22 19:45 UTCGHSA enrichment
  19. 2026-09-22 16:01 UTCEPSS rescore
  20. 2026-09-22 07:57 UTCEG score recompute
  21. 2026-09-22 07:57 UTCGHSA enrichment
  22. 2026-09-21 21:09 UTCEPSS rescore
  23. 2026-09-21 20:29 UTCGHSA enrichment
  24. 2026-09-21 09:01 UTCGHSA enrichment
  25. 2026-09-20 21:34 UTCEG score recompute
  26. 2026-09-20 21:34 UTCGHSA enrichment
  27. 2026-09-20 20:16 UTCEPSS rescore
  28. 2026-09-20 10:06 UTCGHSA enrichment
  29. 2026-09-19 22:37 UTCEG score recompute
  30. 2026-09-19 22:37 UTCGHSA enrichment
  31. 2026-09-19 10:46 UTCGHSA enrichment
  32. 2026-09-18 23:07 UTCEG score recompute
  33. 2026-09-18 23:07 UTCGHSA enrichment
  34. 2026-09-18 19:28 UTCEPSS rescore
  35. 2026-09-18 11:39 UTCGHSA enrichment
  36. 2026-09-18 00:07 UTCEG score recompute
  37. 2026-09-18 00:07 UTCGHSA enrichment
  38. 2026-09-17 11:11 UTCGHSA enrichment
  39. 2026-09-16 23:44 UTCEG score recompute
  40. 2026-09-16 23:44 UTCGHSA enrichment
  41. 2026-09-16 14:08 UTCEPSS rescore
  42. 2026-09-16 12:16 UTCEG score recompute
  43. 2026-09-16 12:16 UTCGHSA enrichment
  44. 2026-09-16 05:15 UTCEPSS rescore
  45. 2026-09-16 00:49 UTCGHSA enrichment
  46. 2026-09-15 13:12 UTCEG score recompute
  47. 2026-09-15 13:12 UTCGHSA enrichment
  48. 2026-09-15 03:12 UTCEPSS rescore
  49. 2026-09-15 03:12 UTCEPSS rescore
  50. 2026-09-15 01:44 UTCGHSA enrichment
  51. 2026-09-14 14:17 UTCGHSA enrichment
  52. 2026-09-14 02:50 UTCEG score recompute
  53. 2026-09-14 02:50 UTCGHSA enrichment
  54. 2026-09-13 15:23 UTCGHSA enrichment
  55. 2026-09-13 03:56 UTCGHSA enrichment
  56. 2026-09-12 16:28 UTCEG score recompute
  57. 2026-09-12 16:28 UTCGHSA enrichment
  58. 2026-09-12 15:02 UTCEPSS rescore
  59. 2026-09-12 05:01 UTCGHSA enrichment
  60. 2026-09-11 17:33 UTCEG score recompute
  61. 2026-09-11 17:33 UTCGHSA enrichment
  62. 2026-09-11 14:53 UTCEPSS rescore
  63. 2026-09-11 05:22 UTCGHSA enrichment
  64. 2026-09-10 17:54 UTCEG score recompute
  65. 2026-09-10 17:54 UTCGHSA enrichment
  66. 2026-09-10 09:35 UTCEPSS rescore
  67. 2026-09-10 06:27 UTCGHSA enrichment
  68. 2026-09-09 19:00 UTCGHSA enrichment
  69. 2026-09-09 07:32 UTCEG score recompute
  70. 2026-09-09 07:32 UTCGHSA enrichment
  71. 2026-09-08 22:01 UTCEPSS rescore
  72. 2026-09-08 20:05 UTCEG score recompute▲ 1.70
  73. 2026-09-08 20:05 UTCGHSA enrichment
  74. 2026-09-08 18:29 UTCNVD updateCVSS v3 → 8.2 · severity → HIGH
  75. 2026-09-08 08:05 UTCEG score recompute

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-77641?
CVE-2026-77641 is a high vulnerability published on August 20, 2026. tor before 0.4.9.9 was prone to a NULL write after free when sending a CONFLUXSWITCH cell fails. The return value of relaysendcommandfromedge() was ignored, so a send failure (which calls circuitmarkforclose() and removes the leg via cfxdelleg()) would go undetected, causing the caller to write to…
When was CVE-2026-77641 disclosed?
CVE-2026-77641 was first published on August 20, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77641 actively exploited?
CVE-2026-77641 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (26th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77641?
CVE-2026-77641 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-77641?
A fix for CVE-2026-77641 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-77641 are linked in the Vendor Advisories panel on this page.

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