SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-26483

SAML Service Providers using this library for SAML authentication support are likely susceptible to Denial of Service attacks.

MEDIUM 5.3EPSS 0.96%

Does this matter?

Lower severity and a low EPSS score (0.96%). Track it; it rarely justifies an emergency change on its own.

Description

gosaml2 is a Pure Go implementation of SAML 2.0. SAML Service Providers using this library for SAML authentication support are likely susceptible to Denial of Service attacks. A bug in this library enables attackers to craft a `deflate`-compressed request which will consume significantly more memory during processing than the size of the original request. This may eventually lead to memory exhaustion and the process being killed. The maximum compression ratio achievable with `deflate` is 1032:1, so by limiting the size of bodies passed to gosaml2, limiting the rate and concurrency of calls, and ensuring that lots of memory is available to the process it _may_ be possible to help Go's garbage collector "keep up". Implementors are encouraged not to rely on this. This issue is fixed in version 0.9.0.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS
0.96% probability · 61th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-409
Affected
gosaml2 project/gosaml2
Source
security-advisories@github.com
EPSS trend
0%3%5%10 October 2026: 0.96%10 October 202610 October 2026

EPSS 1.0% since 10 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.