CVE-2023-26483Network attack vector

Process termination via unbounded SAML decompression

Published Mar 3, 2023 · Updated Feb 25, 2025

Improper compressed-data handling in gosaml2 before 0.9.0 allows remote attackers to cause SAML service-provider processes to be killed. The maybeDeflate helper reads an attacker-supplied DEFLATE stream to completion without an output limit, permitting up to 1,032-fold expansion. Any network-exposed SAML endpoint that passes encoded input to an affected decode path can exhaust memory and terminate its hosting process.

CVSS severity5.3
Medium
EPSS probability0.96%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper compressed-data handling in gosaml2 before 0.9.0 allows remote attackers to cause SAML service-provider processes to be killed. The maybeDeflate helper reads an attacker-supplied DEFLATE stream to completion without an output limit, permitting up to 1,032-fold expansion. Any network-exposed SAML endpoint that passes encoded input to an affected decode path can exhaust memory and terminate its hosting process.

The record

CVE
CVE-2023-26483
Published
Mar 3, 2023
Updated
Feb 25, 2025
Vendor
Russell Haering
Product
gosaml2
Classifications
CWE-409, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Russell Haering · gosaml2version=< 0.9.0

Published CVSS scores

5.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-409Improper Handling of Highly Compressed Data (Data Amplification)
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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