CVE Intelligence
Critical Insecure deserialization exploit reference

CVE-2023-28115 — Snappy vulnerable to PHAR deserialization, allowing remote code execution

Snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page. Prior to version 1.4.2, Snappy is vulnerable to PHAR deserialization due to a lack of checking on the protocol before passing it into the `file_exists()` function. If an attacker can upload files of any type to the server he can pass in the phar:// protocol to unserialize the uploaded file and instantiate arbitrary PHP objects. This can lead to remote code execution especially when snappy is used with frameworks with documented POP chains like Laravel/Symfony vulnerable developer code. If a user can control the output file from the `generateFromHtml()` function, it will invoke deserialization. This vulnerability is capable of remote code execution if Snappy is used with frameworks or developer code with vulnerable POP chains. It has been fixed in version 1.4.2.

Published Mar 17, 2023 · Updated Oct 25, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 2.8% (30-day exploitation probability)+13
  • Technical severity (critical)+10
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

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

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
2.76%
ahead of 86% of scored CVEs · Oct 28, 2026
Affects
KnpLabs
Snappy and 1 more
CVSS base
9.8
Critical · 4 source(s)

CISA SSVC assessment CISA

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

Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)
  • Composer KnpLabs/knp-snappy: fixed in version 1.4.2 — github.com (GitHub Security Advisories)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (KnpLabs Snappy, Composer KnpLabs/knp-snappy).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Search available logs for exploit probes matching the vulnerability class (insecure deserialization), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
KnpLabs Snappy < 1.4.2 Vulnerable NIST National Vulnerability Database
KnpLabs Snappy version < 1.4.2 Vulnerable CVE Program (cve.org) e CISA ADP
Composer KnpLabs/knp-snappy < 1.4.2 Vulnerable GitHub Security Advisories

Attack characteristics

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

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
9.8 CVSS 3.1 Critical 3.9 5.9 security-advisories@github.com via NIST National Vulnerability Database
9.8 CVSS 3.1 Critical 3.9 5.9 nvd@nist.gov via NIST National Vulnerability Database
9.8 CVSS 3.1 Critical — — GitHub, Inc. via GitHub Security Advisories
9.8 CVSS 3.1 Critical — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-502 · Deserialization of Untrusted Data

Other CVEs with this weakness →

EPSS over time FIRST

Oct 25, 2026 → Oct 28, 2026 · 4 reading(s) · max 2.76%

Detection

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

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Monitor serialized objects in requests and unexpected processes spawned by the runtime.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 25, 2026 · GitHub Security Advisories
  • Affected products added · composer/knplabs/knp-snappy
    Oct 25, 2026 · GitHub Security Advisories
  • Affected products added · knplabs/snappy
    Oct 25, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 25, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 25, 2026
  • Fix documented
    Oct 25, 2026 · NIST National Vulnerability Database
  • Affected products added · knplabs/snappy
    Oct 25, 2026 · NIST National Vulnerability Database
  • CVSS changed · 9.8
    Oct 25, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 25, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 25, 2026 · Alertas do Telegram
  • 2023
  • CVE published
    Mar 17, 2023 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 25, 2026 – Oct 25, 2026
  • 1× Official description updated · Oct 25, 2026 – Oct 25, 2026

References

10 on the record

Elsewhere on this site

KnpLabs
every CVE for this vendor
Insecure deserialization
same class
CWE-502
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-46683 Snappy: SSRF and local file read via the xsl-style-sheet option Jun 10, 2026
  • CVE-2026-46643 Snappy: Binary path is never shell-escaped due to an inverted is_executable check Jun 10, 2026

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 record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2023-28115 is "Snappy vulnerable to PHAR deserialization, allowing remote code execution", rated Critical. It affects Snappy (KnpLabs); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 2.76% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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