Coder allows organizations to provision remote development environments via Terraform. Prior to 2.29.19, 2.32.9, 2.33.10, and 2.34.4, agentConn.apiClient() follows redirects while its custom transport accepts the host from the redirected request URL when the port is the workspace agent HTTP API port 4. An authenticated user who controls a modified workspace agent and knows another online agent's UUID can derive the victim's tailnet address and redirect control-plane requests to that agent. HTTP 301, 302, and 303 redirects can redirect read requests, while HTTP 307 and 308 preserve replayable write and process-start requests. The redirected workspace agent file APIs can read or write files as the victim workspace user, and affected versions exposing the workspace agent process API can execute commands after a redirected file write, crossing workspace and tenant boundaries. This issue is fixed in versions 2.29.19, 2.32.9, 2.33.10, and 2.34.4.
CVE-2026-63443
“—” beside the score: it is equal to the CVSS score beside it.
This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.8% (55th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-78927 (ENISA EUVD)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.3
- EG Score
- 8.3HIGHmedium confidence
- EG Risk
- 38EG Risk 38/100
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)Severity83% × 45%Impact severity (EG Severity): CVSS 8.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.8% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.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 none (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. - EPSS PROB
- 0.8%
- EPSS %ILE
- 55th
- 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 (8.3): severity, escalated by confirmed exploitation. This CVE's 8.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.3 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.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).
A fix is available. Apply it within your standard update timelines.
Exploitation none (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.
The score's inputs: 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
September 15, 2026
Last Modified
September 30, 2026
Advisory Details (10)
Auto-updated Sep 15, 2026commit eeb2624549dd (coder/coder)
Fix landed in coder/coder commit eeb2624549dd — awaiting tagged release
https://github.com/coder/coder/commit/eeb2624549ddb85538e493af3e678fdb185a809fcommit ec3ba84c0002 (coder/coder)
Fix landed in coder/coder commit ec3ba84c0002 — awaiting tagged release
https://github.com/coder/coder/commit/ec3ba84c0002f47dd979c073cde1ab345acbaea5commit 812549d671d0 (coder/coder)
Fix landed in coder/coder commit 812549d671d0 — awaiting tagged release
https://github.com/coder/coder/commit/812549d671d0f5a0b45adcee860d37b70aaddccdcommit 2312b67bc52c (coder/coder)
Fix landed in coder/coder commit 2312b67bc52c — awaiting tagged release
https://github.com/coder/coder/commit/2312b67bc52c4e314c18c4b4be5dcf5500c94ad7fix: pin workspace agent API client to intended agent (#26600)
Fix merged in coder/coder PR #26622 on 2026-06-27 — awaiting tagged release
https://github.com/coder/coder/pull/26622fix: pin workspace agent API client to intended agent (#26600)
Fix merged in coder/coder PR #26613 on 2026-06-27 — awaiting tagged release
https://github.com/coder/coder/pull/26613fix: pin workspace agent API client to intended agent (#26600)
Fix merged in coder/coder PR #26612 on 2026-06-27 — awaiting tagged release
https://github.com/coder/coder/pull/26612fix: pin workspace agent API client to intended agent (#26600)
Fix merged in coder/coder PR #26611 on 2026-06-27 — awaiting tagged release
https://github.com/coder/coder/pull/26611fix: pin workspace agent API client to intended agent
Fix merged in coder/coder PR #26600 on 2026-06-23 — awaiting tagged release
https://github.com/coder/coder/pull/26600Workspace agent API insecure redirect handling allowed cross-agent file read and write · Advisory · coder/coder · GitHub
https://github.com/coder/coder/security/advisories/GHSA-qrwj-vh9x-gw5vAffected Packages
(2 across 1 ecosystem)
Go(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| github.com/coder/coder | — |
| — |
| github.com/coder/coder/v2 | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 47× 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.
- 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-28 05:38 UTCEG score recompute
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.8% · 55th percentile
- 2026-10-25 14:13 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-20 18:52 UTCEG score recompute
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-18 03:23 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-13 12:00 UTCEG score recompute
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- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-12 15:49 UTCEG score recompute
- 2026-10-11 19:30 UTCEG score recompute
- 2026-10-11 16:48 UTCEG score recompute
- 2026-10-11 14:10 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-11 05:38 UTCEG score recompute
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-10 04:03 UTCEG score recompute
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-10-09 00:23 UTCEG score recompute
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-10-08 12:11 UTCEG score recompute
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-10-06 22:54 UTCEG score recompute
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-10-05 22:27 UTCEG score recompute
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-10-05 10:12 UTCEG score recompute
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-10-03 21:36 UTCEG score recompute
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-10-02 19:26 UTCEG score recompute
- 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-10-02 07:14 UTCEG score recompute
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-30 18:09 UTCEG score recompute
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-30 01:10 UTCEG score recompute
- 2026-09-29 00:20 UTCEG score recompute
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-27 23:57 UTCEG score recompute
- 2026-09-26 23:01 UTCEG score recompute
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-26 10:50 UTCEG score recompute
- 2026-09-24 22:09 UTCEG score recompute
- 2026-09-23 21:46 UTCEG score recompute
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-22 21:23 UTCEG score recompute
- 2026-09-22 09:11 UTCEG score recompute
- 2026-09-20 20:31 UTCEG score recompute
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-19 20:08 UTCEG score recompute
- 2026-09-18 19:45 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-18 07:33 UTCEG score recompute
- 2026-09-16 18:57 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-15 18:33 UTCEG score recompute
- 2026-09-15 17:32 UTCEG score recompute
- 2026-09-15 16:53 UTCEG score recomputeFirst assessed: 8.3 HIGH
- 2026-09-15 16:52 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Same product
10 shownGo:github.com/coder/coder
Frequently asked(5)
What is CVE-2026-63443?
When was the CVE record for CVE-2026-63443 published?
Is CVE-2026-63443 actively exploited?
What is the CVSS score of CVE-2026-63443?
How do I remediate CVE-2026-63443?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63443
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