CVE-2023-26369VulnerabilityPublished 13 Sep 2023Updated 21 Oct 2025

CVE-2023-26369: Adobe Acrobat Reader · Out-of-bounds Write

Affects Adobe Acrobat ReaderSource CVE Database V5

Exploited in the wild · KEV due 5 Oct 2023 · 6% EPSS : apply the vendor's fix or mitigations to Adobe Acrobat Reader now.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.8High

How severe the flaw is on the 0–10 CVSS scale.

KEV deadline: 5 Oct 2023 US federal agencies must patch by this date; a sensible deadline for everyone else.
EPSS: 6.7% chance of exploitation in 30 days – higher than 93% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 13 Sep 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 1 day after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by adobe
2023-02-2219:47Z, 203 days before disclosure
CVE published
on cve.org
2023-09-1308:17Z, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
2023-09-14, 1 day after disclosure
KEV remediation due
US federal deadline
2023-10-05, 22 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Affected software

Product	Affected	Fixed in
Adobe Acrobat Reader	Affected =0	Fixed in–

Description

Acrobat Reader versions 23.003.20284 (and earlier), 20.005.30516 (and earlier) and 20.005.30514 (and earlier) are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Impact

For European organizations, the impact of CVE-2023-26369 can be substantial. Adobe Acrobat Reader is widely used across industries for document handling, making this vulnerability a vector for targeted attacks or widespread malware campaigns. Successful exploitation can lead to arbitrary code execution, enabling attackers to steal sensitive information, deploy ransomware, or move laterally within networks. Confidentiality is at risk due to potential data exfiltration, integrity can be compromised by unauthorized code execution, and availability may be affected if systems are destabilized or taken offline. Sectors such as finance, healthcare, government, and critical infrastructure in Europe, which rely heavily on PDF documents, are particularly vulnerable. The requirement for user interaction means phishing or spear-phishing campaigns could be used to deliver malicious PDFs, increasing the risk to organizations with less mature security awareness programs. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as threat actors often develop exploits rapidly after disclosure. The vulnerability could also be leveraged in supply chain attacks targeting European companies.

Mitigation

European organizations should implement a multi-layered mitigation approach. First, monitor Adobe’s security advisories closely and apply patches immediately once they become available to eliminate the vulnerability. Until patches are released, restrict the use of Adobe Acrobat Reader by limiting it to trusted users and environments. Employ application whitelisting to prevent execution of unauthorized code. Enhance email security to filter and block malicious attachments, particularly PDFs from untrusted sources. Conduct targeted user awareness training to educate employees about the risks of opening unsolicited or suspicious PDF files. Deploy endpoint detection and response (EDR) solutions capable of identifying anomalous behaviors indicative of exploitation attempts. Consider sandboxing PDF viewers or using alternative PDF readers with a smaller attack surface for high-risk users. Regularly audit and update security policies related to document handling and implement network segmentation to limit lateral movement if a compromise occurs. Finally, maintain comprehensive backups and incident response plans tailored to ransomware and code execution incidents.

CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Oct 2025, 23:00 UTC

WeaknessesCWE-787

Technical details

References

Community reviews

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