VulnerabilityPublished 17 Feb 2026Updated 23 Feb 2026

CVE-2026-2623: Blossom · Path Traversal

Affects BlossomSource CVE Database V5

Public exploit available · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 4.0 base score

5.3Medium

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

EPSS: 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

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 or the CVSS exploit maturity 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

Affected software

Product	Affected	Fixed in
Blossom	Affected =1.17.0 =1.17.1	Fixed in–

AI-suggested

Immediately restrict access to Blossom file upload interfaces to trusted networks or authenticated users only, minimizing exposure to untrusted actors.
Implement web application firewall (WAF) rules to detect and block path traversal patterns such as '../' sequences in file upload requests.
Employ input validation and sanitization at the application or proxy level to reject suspicious file path inputs before they reach Blossom.
Monitor logs for unusual file access or upload activity indicative of exploitation attempts.
If possible, isolate Blossom instances in segmented network zones to limit lateral movement in case of compromise.
Consider disabling or restricting the vulnerable file upload functionality temporarily until a vendor patch or official fix is available.
Keep backups of critical data and configurations to enable recovery from potential file tampering.
Engage with the vendor or community for updates or unofficial patches and apply them promptly once available.

Description

A flaw has been found in Blossom up to 1.17.1. This issue affects the function put of the file blossom-backend/common/common-iaas/src/main/java/com/blossom/common/iaas/blos/BLOSManager.java of the component File Upload. This manipulation causes path traversal. The attack may be initiated remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Impact

The path traversal vulnerability in Blossom could allow attackers to read or write arbitrary files on affected systems, potentially exposing sensitive information such as configuration files, credentials, or proprietary data. Unauthorized file modification could disrupt application functionality or enable further compromise, such as privilege escalation or persistent backdoors. Since the vulnerability can be exploited remotely without user interaction, it poses a significant risk to exposed Blossom instances, especially those accessible over the internet. The medium CVSS score (5.3) reflects moderate impact and ease of exploitation. Organizations relying on Blossom for critical infrastructure or data processing may face operational disruptions, data breaches, or compliance violations if exploited. The lack of vendor response and patches increases the window of exposure, making timely mitigation essential.

Summary

CVE-2026-2623 is a path traversal vulnerability identified in the Blossom software, specifically in versions 1.17.0 and 1.17.1. The vulnerability resides in the put method of the BLOSManager.java file within the file upload component. Path traversal vulnerabilities occur when user-supplied input is not properly sanitized, allowing attackers to manipulate file paths to access files and directories outside the intended scope. In this case, an attacker can remotely craft requests to upload or manipulate files by specifying paths that traverse directories (e.g., using ../ sequences), potentially overwriting critical files or accessing sensitive data. The vulnerability requires low privileges (PR:L) but no user interaction (UI:N) and can be exploited over the network (AV:N) with low attack complexity (AC:L). The impact on confidentiality, integrity, and availability is limited but present, as unauthorized file access or modification can lead to information leakage or disruption of services. The vendor was contacted but did not respond, and no official patches have been released, although a public exploit exists. This increases the urgency for organizations to implement mitigations or workarounds to reduce risk.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Feb 2026, 23:22 UTC

Technical details

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