What is CVE-2026-84267?

CVE-2026-84267 is Gvfs: sftp: uninitialized heap disclosure in read_string(). The supplied enrichment data classifies it as Memory Corruption mapped to CWE-908 CWE-908.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-84267. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-84267 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

1 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-84267 using CVSS 4.3, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

mediumMemory Corruptionpublic exploit

CVE-2026-84267

CVE-2026-84267 — Gvfs: sftp: uninitialized heap disclosure in read_string()

A flaw was found in the SFTP backend in gvfs. When mounting a share, a malicious SFTP server can cause read_string() to allocate a buffer with a certain length but the function does not verify that the buffer is completely filled, leaving the remainder of the buffer containing uninitialized heap contents. If the server sends a short FXP_HANDLE reply, these uninitialized bytes are taken as the file handle. The client will then echo these uninitialized bytes back to the server on all subsequent requests using that handle. With a length of 128 bytes, this issue allows the malicious server to deterministically read uninitialized heap memory from the gvfsd-sftp process, leaking its heap base and the load address of the libgio library, resulting in a deterministic defeat of Address Space Layout Randomization (ASLR).

Published Sep 1, 2026Updated Sep 1, 2026Sources: NVD, Red Hat (CNA), GitHub, GitHub Security Advisory, Red Hat (VEX), SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Exploit code

public exploit, none observed

EPSS

ahead of 0% of scored CVEs

Affects

Red Hat

5 products listed

CVSS base

4.3

medium

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

PoC

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade Red Hat Enterprise Linux 10 to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

Red Hat VEX · CVE-2026-84267

fixed0affected48not affected0

workaround: To mitigate this vulnerability, do not connect to untrusted SFTP servers.

no_fix_planned: Out of support scope

none_available: Fix deferred

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Red Hat	Red Hat Enterprise Linux 10	—	Vulnerable
Red Hat	Red Hat Enterprise Linux 6	—	Vulnerable
Red Hat	Red Hat Enterprise Linux 7	—	Vulnerable
Red Hat	Red Hat Enterprise Linux 8	—	Vulnerable
Red Hat	Red Hat Enterprise Linux 9	—	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

None

Confidentiality

Low

Integrity

None

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

Required

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
4.3	CVSS 3.1	medium	2.8	1.4	NVD, Red Hat (CNA), GHSA, Red Hat (VEX)

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-908 · Use of Uninitialized Resource

Read Memory
Read Application Data
DoS: Crash, Exit, or Restart

Mitigation: Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.

Weakness & attack patterns

CWE-908

Inferred from the weakness class — not observed against this CVE.

CAPEC-100 · Overflow BuffersCAPEC-123 · Buffer Manipulation

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Prioritize edge telemetry for network-reachable Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9.
Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 4.3 (AV:N)
Sep 1, 2026 · NVD
Initial · CVE published
Sep 1, 2026 · NVD
Added · GHSA-7w8w-22g3-g4f8 published (medium)
Sep 1, 2026 · GitHub Security Advisory
CVE published by MITRE.
Sep 1, 2026 · SOCRadar CTI
Reported to Red Hat.
Aug 31, 2026 · Red Hat
Reported · Made public.
Aug 3, 2026 · Red Hat

References

6 on the record

access.redhat.com/security/cve/CVE-2026-84267
Vendor Advisory, NIST
bugzilla.redhat.com/show_bug.cgi?id=2526466
Vendor Advisory, Mitre, NIST
gitlab.gnome.org/GNOME/gvfs/-/issues/861
Vendor Advisory, NIST
nvd.nist.gov/vuln/detail/CVE-2026-84267
NVD
github.com/advisories/GHSA-7w8w-22g3-g4f8
Exploit, Third Party Advisory
www.cve.org/CVERecord?id=CVE-2026-84267
Vendor Advisory

Elsewhere on this site

Red Hatevery CVE for this vendor
Memory Corruptionsame class
CWE-908other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-84267 is Gvfs: sftp: uninitialized heap disclosure in read_string(), a medium vulnerability affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 from Red Hat. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-84267. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 4.3 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.